GA/T 1566-2019Forensic sciences - Code of practice for examination of fax documents (English PDF)

3.1 Identification of inspection materials and samples

The inspection materials and samples shall be uniquely identified.

3.2 Inspection of samples and samples

3.2.1 Form of analysis material.

1) The inspection materials are not formed by fax. Negotiating the inspection unit to change the evaluation requirements shall be carried out or the case shall be withdrawn.

2) The inspection material is formed by fax. Continue to the next step.

3.2.2 Analysis of inspection conditions for inspection materials.

1) If the inspection materials do not meet the inspection requirements, proceed to Chapter 4;

2) If the inspection materials have the inspection conditions, continue to the next step.

3.2.3 Comparison conditions of analysis samples.

1) If the sample does not meet the comparison conditions, the inspection unit is required to supplement the sample or enter Chapter 4;

2) If the samples have comparison conditions, continue to the next step.

3.3 Feature extraction and analysis

3.3.1 Feature extraction method

Direct observation, micro inspection, measurement, spectral analysis and other methods can be used to find and extract the characteristics of samples and samples.

3.3.2 Feature Analysis

Analyze the causes of the features on the samples and samples.

3.4 Comparative test

3.4.1 Method of comparative inspection

The detailed feature comparison method, coincidence comparison method, line drawing comparison method, and measurement comparison method can be adopted.

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3.4.2 Type Identification of Fax Documents

Can be selected from recording method, header code form, manuscript feeding method, reading method, resolution characteristics, halftone level, paper Types and specifications, cutting mouth shape, maximum record width and other factors are comprehensively analyzed and judged.

3.4.3 Identical Identification of Fax Documents

Traces from recording mechanism failures and damage, additional traces formed during scanning of documents, and graphic transmission to analyze the characteristics of traces, such as the traces of contamination and contamination on the fax, you should pay attention to the cause of the traces and analyze the traces.

The interrelationship between traces determines the characteristics of personalized traces.

3.4.4 Component Analysis

If necessary, component analysis can be performed on the test materials and samples.