First, related concepts and their relationships

Handwriting is the trace left by writing action through writing tools, which makes everyone's handwriting unique. Through handwriting, it may reflect the habit of using words and making sentences, that is, the habit of written language; In addition, it may also reflect the writer's character layout habits.

Handwriting inspection is a special technique to determine whether it is the handwriting of the same person or the sample is written by someone by comparing and distinguishing suspicious handwriting with the handwriting of a criminal suspect. Its task is to analyze the time by studying the writing habits, text layout and written language characteristics reflected by handwriting, and to provide clues and evidence for litigation.

Writing habit is a skill gradually formed through long-term practice and writing practice, and it is a firm dynamic stereotype established in the cerebral cortex with language and words as the main stimuli.

Writing habits and handwriting are the relationship between objects and objects reflecting objects. Writing action is expressed by handwriting, and writing habits are reflected in writing action. Writing habits can only be expressed by handwriting and can be recognized and used. Because there is no handwriting, it is impossible to investigate writing habits, but to understand writing habits, we must start with the study of handwriting. Handwriting identification is to determine whether the sample handwriting is reflected by the same person's writing habit system by analyzing and comparing the sample handwriting with the appraiser's handwriting, so as to affirm or deny the sample writer according to the similarities and differences of the habit system and provide a strong basis for judicial action.

Writing habit itself has particularity and relative stability. The specificity of writing habits lies in that each writer's writing habit system is specific and different from others. When writing a manuscript, some habits are possessed by many people, some habits are rare or even unique to some people, and those rare and unique writing habits possessed by * * * constitute everyone's writing. At the same time, writing habits are relatively stable, and its habit system can remain stable for a certain period of time without fundamental changes. The relative stability of writing habits is an indispensable condition for handwriting identification. Writing habit system may be changed by subjective and objective conditions, such as physiological factors, psychological factors, writing tools, personal camouflage, etc., but generally speaking, these changes will not have a fundamental impact on recognition in a certain period of time.

Second, the handwriting characteristics

Handwriting characteristics are the reflection of writing habits. Writing habits and handwriting characteristics are the relationship between reflection and reflection, that is, the relationship between things and objects and reflected images. The most common characters in handwriting identification are Chinese characters, pinyin characters, Arabic numerals and punctuation marks. According to the structure and writing characteristics of Chinese characters, the handwriting characteristics of Chinese characters can be divided into four aspects: the general characteristics of writing action, the characteristics of text layout and the characteristics of written language. This paper mainly discusses the local characteristics of Chinese character writing.

The local characteristics of writing actions are the direct reflection of writing habits, and the concentrated reflection of the spatial position characteristics, action form characteristics, action sequence characteristics and overall characteristics of the text structure composed of several writing actions. The local characteristics of writing actions are the main basis for handwriting identification and identification of writers. Specifically including:

1, writing characteristics. The stroke movement of writing Chinese characters includes three aspects, namely, starting a pen, moving a pen and moving a pen. Writing any stroke has to go through these three stages, so the characteristics of stroke movement are reflected in five aspects: starting characteristics, moving characteristics, moving characteristics, moving characteristics and basic morphological characteristics of strokes.

Because of the different movements of a pen, the whole stroke constitutes a special form, which is called the basic morphological characteristics of strokes, also known as the shape characteristics of strokes. For example, stippling forms vertical points, horizontal points, arc points and sketch points. Stroke movement is the most delicate and complicated writing movement, so it has the characteristics of strong specificity, high stability and high identification value, and is called "the essence of characteristics".

2. The characteristics of stroke crossing, connection and collocation. Refers to the characteristics of the relationship between strokes when two or more pictures form part of a single character or a combined character. There are three relationships between strokes: intersection, connection and adjacency, which form the characteristics of stroke intersection, stroke collocation and stroke connection.

Stroke crossing feature is the feature that two or more strokes cross or approach each other. It shows the positional relationship between the intersection or adjacent points of strokes, that is, whether the strokes cross, cross or not. The characteristics of stroke collocation refer to the characteristics of the mutual position and long-short relationship between strokes, including the proportional relationship between strokes and the overall relationship between individual words. Stroke connection feature means that more than two strokes form a unique character or combined character, which is a connection feature formed by completing several strokes with one stroke in the process of stroke transportation without stopping or collecting.

The characteristics of crossing, connecting and matching of strokes are a special and stable part of personal writing habit system and one of the important bases for handwriting identification.

3. Structural features of Chinese characters. It refers to the characteristics of each component of a combined Chinese character and their relationships. Monograph is a word directly composed of a stroke; A compound word is a word consisting of a stroke and more than two structural units. There are three main structural features of compound words:

(1), written form of structural unit. According to the writing norms of Chinese characters, all parts of the same character have standard writing forms, but due to the differences in writing habits, they may show different writing forms.

(2) Proportional relationship between structural units. Each structural unit of writing Chinese characters requires a reasonable collocation ratio, but most people's habits have broken through this limitation, and its characteristics are: too compact, too loose, asymmetric left and right, uncoordinated size, tight inside and loose outside, tight outside and loose inside, etc.

(3) Variation structure that violates the law of word formation. Because the writer has been influenced by wrong writing habits or regional habits for a long time, he has formed variant structural characteristics that do not conform to the law of word formation.

4, the characteristics of stroke order. It refers to the characteristics of not writing according to the stroke order rules of Arabic and Chinese characters and the writing order rules of components. Shown as:

Special stroke order. Such as vertical before horizontal, pressing before skimming, picking before hooking, etc.

Special writing order between components of combined characters. Break through the conjunction rule, first write the main part of the word together with the strokes, and then write a single stroke that should be written in advance.

5. Special words. Refers to characters that do not exist in the standard font system, but are used in a certain area and a certain group of people. Such as typos, local words, industrial words, coinage, foreign words, etc. Most of them are manifestations of sexual habits and belong to the characteristics of species; A few are unique habits of individuals, so they have high appraisal value.

To sum up, the local characteristics of writing actions often provide a strong basis for handwriting identification in practice, which is of great significance to the development of handwriting identification activities.

Third, the methods and steps of handwriting identification

Handwriting identification is the same identification, and the whole identification process can be divided into three stages: individual inspection, comparative inspection and comprehensive judgment, and each stage has corresponding and different methods.

(a) respectively.

Respective inspection is to find and determine the characteristics of sample handwriting and sample handwriting;

1, to determine the true degree of handwriting characteristics of building materials. According to the characteristics and case of handwriting, accurately judge the change or disguise of handwriting characteristics and the reason and degree of change or disguise.

If the handwriting proficiency of the sample is consistent, the writing level is adapted to the Chinese level, the strokes are natural, the stroke proportion is coordinated, and the writing action is regular, it can be considered as normal handwriting.

For example, the handwriting size and inclination are uneven, the writing speed is inconsistent, the stroke movement is unnatural, and the stroke turning is stiff, but the writing action is systematic to some extent, and the characteristics of the same words and strokes are basically the same, which indicates that it is due to objective reasons or other subjective factors other than camouflage.

If the handwriting proficiency of the sample is inconsistent, the writing action is not systematic, the strokes bend intermittently, there are traces of pause and touch-up, the structure and shape of the characters are abnormal, and the skill of the movements is not commensurate with the Chinese level, it can generally be judged as disguised handwriting.

2. Find and determine the handwriting characteristics of the sample. To find the local characteristics of writing, we must observe the handwriting word by word, draw one by one, and find out the regularity of writing, in which the irregular part is the characteristic.

3. Discover and determine the handwriting characteristics of the sample. After preliminarily judging the handwriting characteristics of the sample, the handwriting characteristics of the sample can be determined according to the above order and method. The same features and different features as the sample handwriting should be comprehensively searched and compared.

(2) Comparative test

The main task of comparison test is to determine the same characteristics and different characteristics between the handwriting of the sample and the handwriting of the sample, so as to provide a basis for comprehensive evaluation.

There are four aspects in the comparative experiment:

Compare the similarities and differences between the general characteristics of writing actions, text layout characteristics and written language characteristics;

Compare the similarities and differences of individual features of words or strokes;

Compare the similarities and differences of each group's characteristics;

Compare the similarities and differences of various characteristics;

For many samples, it is necessary to make an accurate statistical analysis of the same characteristics and different characteristics of the above four aspects, and reflect the similarities and differences of writing habits in quantity and quality by mathematical methods.

The method of comparing the similarities and differences of handwriting features is mainly visual observation, and morphological comparison is carried out with the help of photographic instruments, comparative microscopes and slides.

(3) Comprehensive evaluation

Comprehensive evaluation is to scientifically analyze the numerical values of the same characteristics and different characteristics of sample handwriting and sample handwriting, determine the sum and nature of the coincidence points and differences between them, and then make static conclusions. The method of judgment is generally to start with textual research. When identifying any handwriting, there will be certain differences in characteristics. The key point of judging the difference is to determine the nature of the difference. Its nature has two aspects: essential difference and non-essential difference. Non-essential differences indicate that the proportion of quantity and quality of different features between sample handwriting and sample handwriting is small, while essential differences indicate that the proportion of quantity and quality of different features is large. The former generally shows that they are a reflection of different people's writing habits.

Handwriting identification should not only focus on the judgment of differences, but also on the judgment of overlapping points. It is unscientific to affirm the same conclusion after confirming that differences are non-essential. Coincidence points can also be divided into essential coincidence and non-essential coincidence. If the quantity and quality of the same characteristics of the sample handwriting and the sample handwriting are absolutely dominant, it constitutes essential conformity; If the proportion of the same feature in quantity and quality is small, it belongs to non-essential conformity. After judging the differences and overlapping points, if there are essential differences and non-essential differences between the sample handwriting and the sample handwriting, or the results of essential differences and non-essential differences, it can be concluded whether the sample handwriting and the sample handwriting are written by the same person.