4.4 Examples of typical errors in the production of phonoscopic examination

Lecture



In the production of phonoscopic forensic examination, the requirements of the legislation regulating the forensic expert activity, recommendations developed by the general theory of forensic examination are often not observed, methodological and operational errors are made. Let's name some of them.

1. Experts often make a different examination than the one that the court appointed for them, issue several expert opinions according to one court definition. Instead of a phonoscopic examination appointed by the court, experts on their own initiative make two examinations of different kinds: one “technical expertise of sound recordings”, within which the issue of the presence of phonogram mounting signs is resolved, and the second “phonoscopic examination”, which resolves issues of speaker identification and identification literal content of the conversation on the phonogram, making up not one but two expert opinions on the same definition of the court.

As it is known, the drawing up of different conclusions according to one definition of the appointment of an examination is allowed only during the production of commission examination by experts of one expert specialty, if the conclusions of the commission members differ. In the production of expertise by the same expert, the processing of different expert opinions on the same definition of a court is unacceptable.

2. There is a formal approach to obtaining a subscription that the experts are warned about the responsibility under art. 307 of the Criminal Code for giving a deliberately false expert opinion, when the expert puts the signature under the subscription text after the completion of all studies, after the expert opinion has been drawn up and printed on paper. Thus, the date indicated in the subscription, which indicates the day of the beginning of the examination, does not actually correspond to the action taken - certifying the fact of subscription with a handwritten signature of the expert.

3. The opinion of experts on complex phonoscopic, linguistic, acoustic, and technical expertise of phonograms is not always properly drawn up.

As follows from Art. 8 of the Law on Forensic Expertise, the expert conducts research objectively, on a strictly scientific and practical basis, within the relevant specialty, comprehensively and fully.

However, instrumental studies are often carried out by one expert, and auditory and linguistic analysis is performed by another, while the general conclusion is made on the basis of summing up the results of both studies.

By virtue of par. 5 tbsp. 21 of the Law on Forensic Expertise as part of the commission of experts charged with conducting forensic examination, each expert independently and independently conducts research, evaluates the results obtained by him personally and other experts, formulates conclusions on the questions posed within his specialized knowledge.

In the formation of a general conclusion, only those experts who are competent in assessing the results of both instrumental, and auditory and linguistic analyzes should be involved.

4. The conclusions of experts of phonoscopic examination are not always properly scientifically substantiated and reasoned by the results obtained.

Article 8 of the Law on Forensic Expertise obliges an expert to base an opinion "on the provisions that make it possible to verify the validity and reliability of the conclusions made on the basis of generally accepted scientific and practical data."

According to the existing requirements for the conclusion of a judicial phonoscopic examination, the research part of the conclusion describes the research process and its results, as well as a scientific explanation of the established facts, and sets out:

- the methods and techniques of the studies that are described are accessible for understanding by persons who do not have psychological and linguistic knowledge, in detail, so that, if necessary, one can verify the correctness of the expert’s conclusions by repeating the study;

- data on the used technical means and tools, with an indication of their technical characteristics, the date of the last metrological verification;

- justification and explanation of the applied methods, their validity, error;

- reference and regulatory materials (instructions, decrees, orders), which the expert was guided by in deciding the questions raised, indicating the date and place of their publication;

- expert evaluation of the results of the research with a detailed reasoning of the judgment, justifying the conclusion on the issue being solved1.

The validity of the expert opinion implies the scientific, logical and methodological literacy of the conducted research and the presentation of its results, as well as confirmation of the expert’s conclusions by relevant facts and arguments. This argument, which has an objective character, is a detailed description of the applied methods and the identified features, as well as a detailed description of the course and results of the conducted research.

The methods, means, information on which the expert relies must be scientifically substantiated, tested and reliably established2.

The applied methods should correspond to the modern level of scientific knowledge in this field, generalized expert practice, described in the methodological and scientific literature.

One of the main requirements for the methods used in the production of forensic phonoscopic examinations is the reproducibility of the results - the general principle of scientific knowledge. The absence of references to methods or scientific literature in the conclusion of a phonoscopist expert inevitably raises doubts about the reliability and reliability of the conclusions made and raises additional questions. For example, when searching for traces of computer editing of phonograms, the possibility of traces of digital processing due to modification of phonograms - originals with the help of a special computer program is often overlooked, after which they could be overwritten on any digital or analog media submitted for examination. "The result is an analog phonogram with digital editing. And not every expert will be able to establish it. In many respects, the leading expert institutions of Russia, who have not yet equipped the experts with a full-fledged methodology for researching digital phonograms, are responsible for this situation."

As it is known, scientific analysis is a test by objective methods of subjective impression. In the process of scientific analysis, a scientific concept is developed on the basis of logical and reasoned evidence. In the process of analysis, the properties and qualities that are essential for a given object are distinguished and irrelevant ones are screened out.

The absence in the expert's conclusion of objective signs characterizing the traces of digital processing present on the phonograms makes it possible to evaluate the conducted research as biased, incomplete and not comprehensive, and the conclusions as unreliable and scientifically unfounded.

In no way can it be considered justified in practice the assertions of some experts that "the presence of signs of copying on controversial sound tracks in such cases is not considered as the presence of signs of editing". Modern means of digital processing of phonograms allow for any adjustment of the signal, originally received in digital form. Therefore, in the absence of information about who, how, under what circumstances, using what technical means recorded the original phonograms on a computer disk in digital form, where and how it was stored and how it was copied to analog tapes, only only a conclusion about the absence of signs of installation.

If the experts did not request additional materials or information about what technical equipment was used to produce the sound recording of the negotiations in question, then such incompleteness of the materials submitted for phonoscopic examination creates unavoidable doubts about the correctness of the findings, the objectivity of the study and the good quality of the used materials.

In accordance with GOST 13699-91 "Recording and playing back information. Terms and definitions", editing a phonogram is the union of two or more parts of one or more previously recorded phonograms by overwriting, which can make changes to the recorded information and the order of the fragments can change. The term “phonogram montage” in the scientific literature is defined as an artificial selection of information and a specific sequence on a magnetic phonogram, which consists in deleting, adding, and interrupting or displacing individual fragments of a recording.

All changes or violations of the integrity of the phonogram, as well as the manufacture of a fully assembled recording, are carried out by means determined by the meaning and significance of actions with audio information signals and their sources. These actions can be aimed at reducing the amount of sound (including verbal or acoustic) information, increasing it, rearranging it in a different order, replacing one sound source with another, selecting the necessary information from certain sound sources, as well as combining dissimilar and disconnected time and place of sound signals in a single unit2. Editing can be linear when the sequence, order and content of discrete fragments (elements) of a recording change, and non-linear when the content is changed within an element of a phonogram recorded on a computer disk.

It is known that the development of modern recording technology has greatly simplified the production of electro-acoustic installation through the use of various special mounting devices, as well as selective rewriting to a new (or even the same) tape (audio cassette). The use of digital sound recording tools allows editing and editing of phonograms with almost any required degree of accuracy, leaving virtually no trace of editing transitions. At the same time using high-quality dubbing allows you to completely mask the traces of installation. Modern computer technologies or professional studio equipment hide the traces of editing, smoothing transition areas when inserting or mixing audio signals.

In the literature, expert opinions are often expressed that "in the current situation, when, after an expert’s conclusion about an electronic montage of a phonogram, it is very likely to make a conclusion about its rigging and with insufficiently reliable methods of detecting it, many experts consider it more rational to avoid a definitive conclusion about electronic montage and indicate only for the presence or absence of its signs.2 In this case, the signs of installation themselves can be interpreted ambiguously. "

The wording “signs of installation not available or not found” in some expert opinions of phonoscopic examination can only mean that experts did not reveal signs of installation (for example, due to insufficient sensitivity of measuring equipment, a high degree of error, a large amount of measurement error, as well as for other reasons). It does not follow from this that the phonogram could not be made by editing.

If there are signs of digital processing on phonograms obtained by copying from phonograms that originally resided on a personal computer, the absence of obvious traces of editing does not in principle exclude the possibility of making a phonogram by editing whose traces are intentionally hidden, destroyed or disguised when copied to an analog cassette.

Such a conclusion about the absence of signs of editing on an analog cassette — obtained when copying from a digital phonogram from a personal computer's disk — only indicates that traces (features) of the installation were not found or found (although they can be objectively, they were not noticed by experts, they did not see ).

5. When addressing the issue of identifying signs of phonogram editing, phonograms — copies, rather than phonograms — are sent for phonoscopic examination, the sound recording equipment is not used to produce phonograms.

At the same time, according to the general methodological requirements, in order to correctly conclude that there are no signs of editing primary phonograms using phonogram-copies, it is necessary to compare the phonograms of the copies with the original phonograms. If there are various changes indicating a discontinuity in the fixation of a speech signal, in order to correctly establish the reasons for their occurrence, it is necessary to present the recording equipment used to record the original sound track and make a copy of the sound track.

Therefore, the presentation for examination of primary recordings (originals-phonograms) and sound recording devices is mandatory.

It is possible to establish in an expert way that a digital soundtrack with which a copy was made on an analog cassette has not been monitored, is possible only in one case: if the soundtrack is recorded by a specific digital device that does not allow data to be manipulated.

This is explained by the fact that digital recording differs significantly from its analog properties. From the point of view of expertise, its most important properties are discreteness and non-distortion during transmission and storage. These properties of digital recording make it difficult to diagnose the fact of copying in cases where the recording device allows you to replace the data medium or copy the data from the computer to another medium.

In an analog recording, a captured signal is represented as a continuous function physically associated with the properties of a particular carrier. Any artificial changes in the information cause a discontinuity in the function of the signal, which in most cases can be established by an expert.

In digital recording, the captured signal is represented as a discrete sequence of values ​​that do not have a physical connection between themselves and the information carrier. If a digital recording of a producer from a sound source directly to a hard disk of a computer, then it may be subject to various modifications and procedures: copying, erasing, editing, editing - without showing signs of change.

The digital representation of audio data allows almost any manipulations with them without identifying the primary signs of installation.

In some cases, changes in the primary digital information can be established by expert analysis on “secondary” grounds, which are due to low qualifications or errors of the operator who manipulates the primary information, low quality and technical limitations of the equipment, i.e. not in every case.

When copying a digital phonogram, which has been manipulated, modified, and mounted on an analog carrier, the “secondary” features may be lost and masked. Therefore, in general, it is not possible to determine the reliability of an analog phonogram obtained by copying from a digital phonogram, the recording conditions of which are unknown. Such phonograms in procedural terms do not have a judicial perspective, since it is not possible to confirm the accuracy of the phonograms recorded on them by expert means.

Identification studies are also connected with the question of the integrity of a phonogram: linguistic syntactic features can be involved only if the possibility of making a phonogram by editing is reliably excluded.

As you know, electronic digital editing (or non-linear) digital soundtrack editing is carried out using any sound editor (sound processing software). In this case, the sound signal is numerically broken into fragments, which are joined in the required sequence with each other. Then, each joint - the editing transition - and the entire soundtrack located on the hard disk of the computer is processed by various filters and signal editing programs. The final mounted phonogram is output via a digital-to-analog converter (available in the bundle of any multimedia computer) of a computer and recorded onto a conventional tape cassette using a tape recorder.

Modern audio editors in digital form have many means for changing the level, timbre, spectrum and many other properties of the processed signal. The operator processing the phonogram controls the result by hearing and visually, looking at the signal patterns (waveforms, spectrograms, etc.). All this technology used for editing musical works has received widespread mass distribution on television and radio.

Если кто-либо выполняет монтаж новой фонограммы на основе цифровой записи одной или нескольких фонограмм переговоров абонентов, ведущих переговоры по сотовой телефонной сети, например GSM, то при размещении точек монтажных переходов в паузах между репликами разговора обнаружение таких точек монтажного перехода является сложной задачей, требующей особых методов исследования. Выполнить такой монтаж несложно, а вот обнаружить его следы при перезаписи на аналоговую кассету затруднительно. Это объясняется тем, что на участках речевых пауз по самой природе цифрового кодирования по алгоритму GSM имеется не реальный звуковой сигнал, а искусственный сигнал "комфортного шума". В случае использования для монтажа фонограмм, в которых переговоры велись абонентами в одной и той же относительно тихой окружающей обстановке с одних и тех же телефонных аппаратов, обнаружить на участках монтажных переходов простые признаки монтажа обычно не представляется возможным, поскольку между репликами стандартной фонограммы в GSM-канале имеются участки вставки искусственного "комфортного" шума.

It is practically impossible to distinguish the sections inserted by the GSM coding algorithm itself during transmission of artificially inserted noise sections along with subsequent replicas during the installation of the phonogram, as there are no clicks, jumps of the level and frequency range of the noise, on / off pulses in the places of such transitions. a) recording equipment, pieces of words or phrases, violations of the logical unity of conversations.

On the phonogram of telephone conversations, which were conducted via cellular communication, falsified with the help of computer editing, they were recorded on digital media, and then were recorded on a usual analog compact cassette, there may be no obvious signs of editing. To detect such a montage, it is necessary to use more complex technical analysis procedures, for example, the correlogram and phase analysis of the phonogram signal.

6. При проведении идентификационных исследований не всегда правильно и полно применяются все рекомендованные экспертные методики. Так, например, в распоряжение эксперта должны, как правило, представляться "оригиналы фонограмм, подлежащие исследованию", "тексты всех фонограмм", "установочные данные на подозреваемого (сведения о месте и дате рождения, национальности, родном языке, образовании, специальности, профессии, месте наиболее длительного проживания, знании иностранных языков", "информация о технических условиях звукозаписи (дата, время, тракт передачи, тип магнитофона и микрофона, характеристика помещения)".

К ошибкам может привести и проведение идентификационных исследований голоса и речи не по фонограммам-оригиналам, а по фонограммам-копиям, которые могли быть изготовлены путем монтажа, без учета технических условий производства записи первичных фонограмм в цифровой форме на диске компьютера и последующего их копирования на аналоговый носитель. Тем самым нарушается основное методологическое требование методики "Диалект" об оценке всех параметров тракта передачи и записи сигнала для оценки достоверности идентификационно значимых признаков. Согласно названной методике типовые фонограммы, по которым может быть проведен полный комплекс идентификационных исследований и вычислены все предусмотренные в системе "Диалект" признаки, должны отвечать следующим требованиям:

- средний диапазон частот: от 0 до 3700 Гц;

- non-uniformity of the amplitude-frequency characteristic of the phonogram receiving path (in the band from 200 to 3400 Hz) - not more than 15 dB;

- detonation and change in speed of movement of the sound carrier - no more than 2%;

The average value of the signal-to-noise ratio is at least 15 dB. The duration of the phonograms of an unknown person must be at least 30 s, the suspected person (i.e. speech patterns) must be at least five minutes. To conduct research on individual comparable fragments of speech in a phonogram there must be at least 10-15 identical words.

Если же фонограммы переговоров, поступившие на экспертизу на компакт-кассетах, были получены путем их первоначальной записи на диске компьютера в цифровой форме с последующей перезаписью на аналоговую кассету, а сами переговоры лиц, подлежащих идентификационному исследованию, велись по сотовой мобильной связи, то должны быть представлены на экспертизу и данные об условиях звукозаписи. Это положение имеет принципиальный методологический характер, который заключается в том, что в случае записи переговоров по сотовой связи исследованию подлежит синтезированный речевой сигнал, из которого алгоритмом кодирования могут быть исключены многие существенные идентифицирующие диктора особенности, а некоторые существенно искажены. Без решения вопросов достоверности воспроизводимого сигнала и границ допустимости его искажений в канале сотовой связи, использованном абонентами на спорных фонограммах, экспертное заключение по идентификации говорящего не может быть полным и достоверным. Такое требование обусловлено тем, что для отождествления говорящего необходимо выявление индивидуального комплекса акустических и лингвистических признаков, определенных на всех элементах, составляющих структуру речи.

7. Как показывает экспертная практика, участники судопроизводства все чаще стали уделять пристальное внимание техническим средствам и приборам, при помощи которых производятся различные измерения в ходе экспертного исследования. По мотивам применения приборов, не являющихся сертифицированными средствами измерений, не проверенных в установленном порядке, заключения эксперта признаются недопустимыми доказательствами, полученными с нарушением Федерального закона от 26.06.2008 № 102-ФЗ "Об обеспечении единства измерений".

В современной судебно-экспертной деятельности, которая основывается на принципах законности, независимости эксперта, объективности, всесторонности и полноты исследований, проводимых с использованием современных достижений науки и техники, особое значение приобретают измерения. Основа применяемых экспертом научно обоснованных методов и методик - достоверная исходная информация, которая может быть получена лишь путем измерения требуемых физических величин, параметров и показателей, объективно отражающих свойства объектов экспертизы. При производстве судебной экспертизы измерения позволяют свести до минимума субъективную сторону чувственного созерцания и в конечном счете добиться максимальной точности результатов, насколько это позволяет природа измеряемых объектов и тип применяемых средств измерений1. Естественно, что только высокая и гарантированная точность результатов измерений обеспечивает правильность принимаемых экспертом решений и достоверность его выводов. Метрологическое обеспечение судебно-экспертной деятельности - важный фактор, позволяющий на практике реализовать защиту граждан и юридических лиц от недостоверных результатов измерений при производстве судебных экспертиз, влекущих не только экспертные, но и судебные ошибки.

Так, например, старшим следователем ОРОВУД Следственного управления Следственного комитета при прокуратуре РФ по П-му краю А. в ходе расследования уголовного дела было вынесено постановление о назначении фоноскопической экспертизы, производство которой было поручено эксперту ООО "Независимая экспертиза". In accordance with Part 3 of Art. 86 УПК, п. 3 ст. 6 Федерального закона "Об адвокатской деятельности и адвокатуре в Российской Федерации" адвокатом был направлен запрос в названную коммерческую организацию с просьбой ответить на следующие вопросы:

1. В соответствии с требованиями Федерального закона "Об обеспечении единства измерений" проводилась ли метрологическая аттестация аппаратуры, указанной в заключении эксперта ООО "Независимая экспертиза", использованной для проведения фоноскопической экспертизы по уголовному делу?

2. Внесена ли данная аппаратура в государственный реестр средств измерений и сертифицирована ли она Ростехрегулированием?

3. Определена ли суммарная погрешность измерений данной аппаратуры (методическая, инструментальная и иные составляющие погрешности)? Если да, то проводилась ли поверка измерительного оборудования?

4. Какие методики измерений использовались экспертом ООО "Независимая экспертиза" при проведении фоноскопической экспертизы?

В связи с тем, что на все указанные вопросы был получен отрицательный ответ, т.е. аппаратура, на которой проводилось исследование по фоноскопической экспертизе, не была внесена в государственный реестр средств измерений', суммарная погрешность измерений данной аппаратуры не определялась, ежегодная поверка измерительного оборудования не проводилась, методики измерений акустических параметров фонограмм не аттестованы, то по ходатайству адвоката заключение эксперта было признано судом недопустимым доказательством.

При этом суд в своем постановлении указал, что в приведенном в заключении эксперта списке аппаратуры для проведения исследований не указаны сведения о сертификации и внесении указанной аппаратуры в государственный реестр средств измерений, не оценивается суммарная погрешность измерений. Это свидетельствует о необоснованности применения аппаратуры в уголовно-процессуальной практике, так как вопросы возможных погрешностей в полученных при использовании несертифицированной аппаратуры выводах не имеют ответов. А выводы, сделанные на основе исследований с применением несертифицированной аппаратуры и неаттестованных методик измерений физических величин, не могут считаться достоверными в силу указанных выше причин.

В связи с этим укажем, что для достижения точности результатов измерений, осуществляемых при производстве экспертизы, к характеристикам (параметрам) измерений, влияющим на результат и показатели точности измерений, а также к условиям, при которых эти характеристики (параметры) должны быть обеспечены, и средствам измерения, используемым при производстве экспертизы, предъявляются определенные требования. Основными свойствами результатов измерений являются их точность, правильность, сходимость и воспроизводимость. Результат измерения должен быть получен с соблюдением норм действующих действующего законодательства и нормативных технических документов, обеспечивающих единство измерений.

Задачи инновационного развития экспертных методик, совершенствование приборной базы за счет внедрения в экспертную деятельность высокотехнологичных методов и прецизионных средств исследования материальных объектов, поступающих на экспертизу, невозможны без развитого метрологического обеспечения, основанного на установленных правилах обеспечения единства измерений, государственной эталонной базе и государственном метрологическом контроле.

Действующая до недавнего времени нормативно-правовая база, регулировавшая отношения в области обеспечения единства измерений, перестала соответствовать современным социально-экономическим условиям развития общества, задачам и процессам глобализации. В связи с этим был принят новый Федеральный закон "Об обеспечении единства измерений", отвечающий международным требованиям и современному российскому законодательству1. В данном Законе регламентированы формы государственного регулирования в области обеспечения единства измерений: утверждение типов стандартных образцов и средств измерений, поверка средств измерений, метрологическая экспертиза, аттестация методик (методов) измерений, аккредитация метрологических служб2. Закон регулирует отношения, возникающие, в частности: при выполнении измерений; установлении и соблюдении требований к измерениям, единицам величин, эталонам единиц величин; при применении методик измерений; при осуществлении деятельности по обеспечению единства измерений. Сфера государственного регулирования обеспечения единства измерений распространяется на все измерения, к которым установлены обязательные требования и которые выполняются по поручениям суда, органов прокуратуры, государственных органов исполнительной власти (п. 16 ч. 3 ст. 1 Закона).

В Федеральном законе "Об обеспечении единства измерений" определяется понятие "единство измерений" - состояние измерений, при котором их результаты выражены в допущенных к применению в Российской Федерации единицах величин, а показатели точности измерений не выходят за установленные границы.

Единство измерений при производстве судебных экспертиз позволяет обеспечивать сопоставимость результатов измерений, выполненных в различных местах и в различное время при помощи различных средств измерений. Только такое состояние измерительной техники позволяет достоверно сравнивать между собой объекты и процессы, свойства которых определяются числовыми характеристиками.

Обеспечение единства измерений в судебно-экспертной деятельности является важнейшим условием защиты прав и законных интересов граждан, юридических лиц и индивидуальных предпринимателей от отрицательных последствий недостоверных результатов измерений, позволяет удовлетворить потребности государства и общества в получении объективных, достоверных и сопоставимых результатов измерений при проведении разнообразных экспертиз в судопроизводстве.

Применительно к судебно-экспертной деятельности можно прогнозировать, что Закон, не решив старых проблем, может породить новые, усугубив практику признания заключений экспертов, содержащих результаты измерений физических величин (например, параметров времени, частоты и т.д.), недопустимыми доказательствами, полученными с нарушением требований Закона.

Одна из таких проблем связана с сертификацией оборудования, используемого экспертами при производстве экспертиз. Закон требует, чтобы все измерения физических величин проводились на сертифицированном и поверенном оборудовании с установленной погрешностью, а методики выполнения измерений должны быть утверждены в установленном порядке. При этом особые проблемы возникают при сертификации сложных вычислительно-измерительных комплексов, в состав которых входят аналого-цифровые преобразователи и программные средства, эмулирующие аналитические приборы (спектро-анализаторы, вольтметры и т.д.). Существующая практика сертификации в качестве средства измерений АЦП-ЦАП, входящих в состав автоматизированных рабочих мест (АРМ) экспертов, единична.

Принятие Федерального закона "Об обеспечении единства измерений" - это, с одной стороны, укрепление сферы государственного регулирования в области обеспечения единства измерений, а с другой - отмена лицензирования деятельности по изготовлению и ремонту средств измерений. Полномочия по поверке средств измерений в целях утверждения их типа и аттестация методик (методов) проведения измерений передаются аккредитованным организациям. Нормами Закона урегулированы вопросы проведения обязательной и добровольной метрологической экспертизы. Кроме того, в целях обеспечения открытости и доступности информации для всех заинтересованных лиц создастся Федеральный информационный фонд и области обеспечения единства измерений.

These provisions are of particular importance for the measurements made in the forensic phonoscopic examination. Measurements should be carried out according to certified measurement methods (methods), with the exception of measurement methods intended to perform direct measurements, using approved-type measuring instruments that have passed the calibration. Certification of measurement methods (methods) - research and confirmation of compliance of measurement methods (methods) with established metrological requirements for measurements.

Methods (methods) of measurement, designed to perform direct measurements, are entered in the operational documentation for measuring instruments. Confirmation of compliance of these methods (methods) of measurements with the mandatory metrological requirements for measurements is carried out in the process of approval of data types of measuring instruments. In other cases, the confirmation of compliance of the measurement methods (methods) with the obligatory metrological requirements for measurements is carried out by means of certification of measurement methods (methods).

Information on certified measurement methods (methods) are transferred to the Federal Information Fund for ensuring the uniformity of measurements by legal entities and individual entrepreneurs conducting certification. Attestation of measurement methods (methods) related to the state regulation of ensuring the uniformity of measurements is carried out by legal entities and individual entrepreneurs accredited in the established procedure in the field of ensuring the uniformity of measurements.

The reliability of the findings of a phonoscopist expert conducting an acoustic or technical study of phonograms directly depends on the measurement tools used by him. The term "measuring instruments" refers to technical devices intended for measurements and having normalized metrological characteristics, i.e. characteristics that affect the results and accuracy of measurements and allow to estimate the measurement errors made in known conditions. If the metrological characteristics of the measuring instrument are unknown, its use in the production of forensic examination does not make sense, since it is impossible to estimate the measurement error and, as a result, check the accuracy of the expert’s conclusions.

Metrological characteristics of measuring instruments are those characteristics that determine the accuracy of measurement results performed using these tools. In forensic activities for measuring can only be used attorneys measuring devices of the approved type. The mandatory requirements for measuring instruments in necessary cases also include the requirements for their component parts, software and operating conditions for measuring instruments. When using measuring instruments, the mandatory requirements for the conditions of their operation should be observed. The procedure for attributing technical means to measuring instruments is established by the federal executive body that performs the functions of state policy development and legal regulation in the field of ensuring the uniformity of measurements.

Verification of measuring instruments - a set of operations performed in order to confirm the compliance of measuring instruments with metrological requirements. In other words, the verification of measuring instruments used in the production of forensic examinations is necessary in order to be able to trust the results obtained and to make sound conclusions based on these results. At the same time, the term “ verification” cannot be substituted by the term “ verification” - verification of the device’s operability

The design of modern measuring instruments should provide access restriction to certain parts of measuring instruments (including software) in order to prevent unauthorized tweaking and interference, which can lead to distortions of measurement results.

Further, the measurement results should be expressed in legal units, and measurement errors should not go beyond the established boundaries with a given probability. In metrology, measurement is defined as the procedure for once finding a quantitative value of a physical quantity empirically. Measurement in the forensic expert activity is one of the general scientific methods and is carried out by comparing the quantity being studied with its uniform unit of measure, and a quantitative ratio of known and unknown quantities is established.

The measurement procedure is a system of operations, effects and measurements, which in these conditions ensures obtaining with a certain accuracy the results of measurements of a physical quantity in accordance with the purpose of the measurement task. A measuring system is defined as a set of measuring instruments and auxiliary devices that measure the totality of physical quantities characterizing the object of measurement in terms of its functioning or change. The quality of measurements is understood as a set of properties of the state of measurements that provide obtaining the results of measurements with the required accuracy, in the required form and at a stated time.

Measurement quality is a set of measurement properties that determine the conformity of the method, means, methodology, conditions, and state of measurement uniformity to the requirements of the measurement task.

The quality of the means and measurement results is characterized, indicating their errors.

The error is the difference between the measurement result and the true value of the measured value. In metrology, it is defined as the difference between the measured and true values ​​of a physical quantity. Similarly, measurement errors are defined as deviations of measurement results from the true values ​​of the measured quantity. Characteristics of the measurement error ensure the accuracy of the results.

Among the variety of types of errors present in measurement problems (for example, by the type of description - systematic, random, random statistically stable, rough, expert misses, etc.), it is necessary to single out the errors by source - methodical and instrumental. Instrumental measurement errors are the components of measurement errors caused by measuring instruments. Methodical measurement errors are components of measurement errors due to mathematical models used in the measurement procedure (and, consequently, mathematical measurement algorithms). Thus, errors in measurements are associated with a violation of the conditions of application of the methods and means of measurement used and the processing of measurement results2.

It is possible to compare the results of measurements obtained using different measurement procedures (or measurement methods) only if the characteristics of the total measurement error are known for each of the procedures (methods). This is especially important to ensure that the expert’s conclusions can be checked in the conditions of legal proceedings on the basis of generally accepted scientific data.

Measurement results obtained using measuring instruments that are not included in the state register or on untested devices cannot be used to establish facts that are important evidence when conducting forensic examination. Thus, all measuring instruments of physical quantities used in forensic examination are subject to metrological verification, they must be included in the state register of measuring instruments and the total measurement error, including methodological, instrumental and other error components, must be determined for them.

In order for a measurement procedure to become a measurement procedure, it must be stated in a document (and not in a reference book, in a report, in a textbook, etc.), it must be assigned by the developer (under his personal responsibility) certain numerical values ​​of the selected measurement error characteristic, which are guaranteed by the developer when all the requirements of the document are met. That is, the measurement method of any physical quantity establishes a set of operations and rules, the implementation of which in these measurement conditions ensures that its value is obtained with the required accuracy. This document must contain clearly and unambiguously formulated requirements for the procedure for measuring physical quantities during forensic examinations.

It must be emphasized that the concept of "measurement" in the forensic examination is inextricably linked with the concept of "calculation". But one concept can not replace another.

Let us explain by the example of phonoscopic examination.

It is known that measurement is a set of operations performed to determine the quantitative value of a quantity. Using appropriate methods and measuring instruments (for example, a spectrum analyzer), the measured value (for example, frequency) is compared with the unit of measurement (for example, Hertz). The result of the comparison is a relative value (number). The obtained quantitative characteristic of some property of the measured object with the corresponding unit of measurement is the result of measurement.

Computation - the execution of arithmetic and logical operations by a human, computer or other device. That is, to calculate - it means, having performed an action on numbers, to find the desired one. Calculation is the secondary processing of data using mathematical models and algorithms, while the initial (primary) quantitative data are objectively obtained as a result of measurements. In order to perform some calculation, it is necessary to obtain quantitative results of measurements of the original physical quantities. Note that when conducting a forensic examination, it is impossible to conduct abstracted from a particular object of examination “computations” without basing on specific data obtained as a result of the “measurements” of a specific object received for a forensic expert study.

In this connection, the erroneousness of sometimes existing statements that “the acoustic parameters of a speech signal during phonographic examination are calculated and not measured are becoming obvious. None of the hardware used in the production of expertise is a measure, is not used as a measure, to be verified as a measurement tool. " Note that it is impossible to carry out calculations without objectively basing on specific data obtained as a result of measurements of physical quantities (parameters) on a specific object. If there are no primary data in the form of measured physical quantities, then there is nothing to calculate.

In the phonoscopic (phonographic) examination, the procedure for instrumental investigation of the acoustic parameters of a speech signal consists in measuring various parameters of the incoming phonogram, i.e. objectively obtaining quantitative indicators of acoustic parameters1, which are further subjected to various computational procedures in the framework of the application, for example, of the method for identifying persons by voice and speech on the Dialect system 2.

Conducting basic measures for the metrological support of forensic science activities (verification, calibration, repair of measuring instruments) directly affects the accuracy of measurement results, the safety of people, as well as the legal justification for the use of technical means in the production of forensic examination. Therefore, substitution of the notion “measurement” with the notion “calculation” is unacceptable, as well as unacceptable when the verification of a measuring instrument is replaced with the notion of operability testing or equipment testing.

In connection with the expansion of adversarial proceedings, the possibility of attracting specialists to clarify to the parties and the court issues, including those related to the field of metrology, it can be predicted that failure to comply with the production of examinations of metrological rules and standards for obtaining reliable measurement information may result in invalid expert results. and conclusions - scientifically unfounded.

Bearing personal responsibility for his conclusion (including criminal), the expert is obliged to use certified attorneys measuring instruments and certified measurement methods with an indication of errors. Only such an approach will exclude the possibility of disputes over the reliability and validity of an expert opinion in an adversarial legal process and, moreover, will allow, if necessary, to repeat the measurements, checking their accuracy and reliability.


Comments


To leave a comment
If you have any suggestion, idea, thanks or comment, feel free to write. We really value feedback and are glad to hear your opinion.
To reply

Right

Terms: Right