GA/T 1576-2019Forensic sciences - Automated firearms identification system (AFIS) (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

Please note that some elements of this document may involve patents. The issuer of this document is not responsible for identifying these patents.

This standard was proposed and managed by the National Criminal Technology Standardization Technical Committee Trace Inspection Sub-Technical Committee (SAC/TC179/SC9).

This standard was drafted. Beijing Institute of Criminal Science and Technology, Beijing Langyuechuan Technology Co., Ltd.

1 Scope

This standard specifies the specifications for the entry of bullet marks into the automatic identification system for bullet marks.

This standard applies to the application and management of the automatic identification system of forensic scientific bullet marks.

2 Normative references

The following documents are essential for the application of this document. For dated references, only the dated version applies to this document.

For undated references, the latest version (including all amendments) applies to this document.

GB/T 29347-2012 Forensic Science Firearms Shell Trace Inspection Specification GB/T 29348-2012 Forensic Science Firearms Shooting Bullet Trace Inspection Specification GA/T 1506-2018 Forensic Science Bullet Mark Inspection Terms

3 Terms and definitions

Bullet mark

When the warhead squeezes into the rifling and rotates forward in the bore, it is formed by the effects of squeezing, shearing, and friction.

Rifling mark

During the extrusion process of the warhead, the surface of the armor was formed into a concave band-like mark by the squeezing and shearing and frictional effects of the inner surface of the rifling. include Traces of rifles and burles.

Number of grooves

The number of yin and rifle marks on the firing warhead.

Width of the rifling the vertical distance between two adjacent ridge marks in the rifle marks (veterin or breech).

Direction of twist

The direction of rotation of the barrel rifle, the direction of rotation of the rifled barrel is divided into left and right.

Incline of rifling

The inclination angle of the rifling marks relative to the axial direction of the warhead.

Small line marks

When the warhead squeezes into the rifling and rotates forward in the rifle, the surface of the warhead is formed by the squeezing and friction of the inner surface of the rifling and is distributed in the firing.

Strike the cylindrical part of the warhead, and there are many linear scratches with a certain slope.

Driven edge of the land mark During the squeezing of the warhead, when the warp armor's surface directly affected by the inner surface of the rifle is compressed and deformed, the sides of the rifle are cut at the sides.

Into the armor, two edges of the rifled marks were formed due to shearing. The warhead was embedded in the rifling, and the gun rifled turned to act on it.

The side of a ridgeline trace in the middle exerts normal force and steering friction, so a clear and thick main ridgeline trace is formed on the firing warhead.

Primary mark

The mark formed by the warhead's squeezing into the rifle.

3.10

Secondary mark

Traces formed after the warhead was squeezed into the rifle.

3.11

Indicator mark

The mark formed by the interaction of the front end of the indicator rod and the bottom surface of the cartridge case.

3.12

Firing pin mark

The striker hits the bottom fire with a certain kinetic energy and presses against the bottom of the shell, which causes the bottom fire cap to produce marks formed by local deformation and strike the needle hole.

3.13

Tongue mark

When the needle head that is in direct contact with the bottom flame cap and its corresponding side edge of the needle head trace are relatively displaced, it is formed due to friction.

Of tongue-shaped prying marks.

3.14

Breechface mark

Under the action of gunpowder gas pressure, the bottom surface of the cartridge case is tightly pressed against the bottom socket of the gun machine to form an imprint mark.

3.15

Ejector mark

A kind of impact mark and ejector mark formed on the bottom edge of the shell (usually on the edge of the sign surface) of the ejection shell end surface.

3.16

Automatic firearms identification system (AFIS) Use computer technology, pattern recognition technology and network technology to collect gun trace data, and A computer application system for processing, storing, comparing and assisting identification of related information.

3.17

Expanded bullet view the expanded image formed by 360 ° rotation of the warhead.

3.18

View of bullet rifling mark an image formed by splicing a single warhead rifle trace.

4 Shot trace image properties and format

6 Bullet trace code

7 Bullet case and warhead trace collection parameters

For the parameters of the shell trace collection, see Table A.1 in Appendix A, and for the parameters of the bullet trace collection, see Table B.1 in Appendix B.

Appendix A

(Normative appendix) Cartridge trace collection parameters the parameters of the cartridge case collection are shown in Table A.1.

Table A.1 Collection parameters of cartridge case traces

Classification orientation drawing number 1951 type 7.62mm Pistol (1954 pistol, 1979, 1985 type light submachine gun and shooting 1951 type 7.62mm Modified or self-made pistols support) Shell throwing

12 Points, side

Edge vertical or water Flat and tongue mark 3 points 8 ring light C graph and B Graph hold Same place 15.63 9 o'clock on the side 20 ring light

25 Points at 9 o'clock

40 Points at 12 o'clock

31.25 Ring Light

Table A.1 (continued)

1964 type 7.62mm

Pistol

(1967 and 1977 style pistols) Shell throwing 12 points 9 ring light Picture C and Picture B Hold the same position 15.63 9 o'clock on the side 25 ring light 40 points at 9 o'clock

31.25 Ring Light

Table A.1 (continued)

1956 type 7.62mm

Rifle ammunition

(1956, 1981 style rifles) Shell throwing 12 points 12.5 × 0.5 Ring light Side light Picture C and Picture B Hold the same position 12.5 9 o'clock on the side

15.63 Ring Light

25 points at 9 o'clock

31.25 Ring Light

Table A.1 (continued)

1953 type 7.62mm

Rifle ammunition

(1953 rifle)

Shell throwing

12 points

10 × 0.5

Ring light

Side light

Picture C and Picture B Hold the same position 12.5 9 o'clock on the side

15.63 Ring Light

20 points at 12 o'clock

31.25 Ring Light

Table A.1 (continued)

11.43mm

Pistol

Tongue mark 3 points 12.5 × 0.5 Ring light Side light Picture C and Picture B Hold the same position 12.5 9 o'clock on the side

15.63 Ring Light

40 points at 9 o'clock

31.25 Ring Light

Table A.1 (continued)

5.6mm

Sports bullets (side firing) Pinhole marks 12 points 10 ring light 9 points on 10 sides

31.25 Ring Light

31.25 9 o'clock on the side

Table A.1 (continued)

5.56mm

Rifle ammunition

Shell throwing

12 points

10 ring light

Picture C and Picture B Hold the same position 15.63 9 o'clock on the side 25 ring light 40 points at 9 o'clock

31.25 Ring Light

Table A.1 (continued)

5.8mm pistol

Shell throwing

12 points

9 ring light

Picture C and Picture B Hold the same position 15.63 9 o'clock on the side 25 ring light 40 points at 12 o'clock

31.25 Ring Light

Table A.1 (continued)

5.8mm rifle round

(5.8 Rifle, 1988

(Slam Rifle)

Shell throwing

12 points

12.5 × 0.5

Ring light

Side light

Picture C and Picture B Hold the same position 12.5 9 o'clock on the side

15.63 Ring Light

40 points at 9 o'clock

31.25 Ring Light

Table A.1 (continued)

6.35mm

Pistol

Shell throwing

12 points

10 ring light

Picture C and Picture B Hold the same position 15.63 9 o'clock on the side 25 ring light 40 points at 9 o'clock

31.25 Ring Light

Table A.1 (continued)

Number 16

Shotgun shell

8 × 0.5 ring light

Picture C and Picture B Hold the same position 9 points on 10 sides

15.63 Ring Light

15.63 9 o'clock on the side

31.25 Ring Light

Table A.1 (continued)

12th

Shotgun shell

8 × 0.5 ring light

Picture C and Picture B Hold the same position 9 side 9 points

15.63 Ring Light

15.63 9 o'clock on the side

31.25 Ring Light

Table A.1 (continued)

9mm runner

Pistol

Breech marks

Straight, strike

Upward bias

8 ring light

Picture C and Picture B Hold the same position 15.63 9 o'clock on the side 20 ring light

31.25 Ring Light

Table A.1 (continued)

9mm × 17

9mm × 18

9mm × 19

Pistol

(Including 59 and 92 pistols, Type 82 light submachine gun) Shell throwing 12 points 8 ring light

Figure C and Figure B

Hold the same position 15.63 9 o'clock on the side 20 ring light 40 points at 12 o'clock

31.25 Ring Light

Note 1. The bottom of the cartridge case is wiped clean, and the characteristic reflection is obvious.

Note 2. The positioning is accurate, the lighting is accurate, and the file name is correct.

Appendix B

(Normative appendix) Warhead trace collection parameters the warhead trace collection parameters are shown in Table B.1.

Table B.1 Collection parameters of warhead traces

Gun multiples

Stepping

speed

/step)

collection

Step count

(step

Vegetarian

Light angle

exposure

time

full image

splice

splice

1964 style

7.62mm

Pistol

25.200 500 5 45 ° ± 5 ° 169 40 45 ° ± 5 ° 169 1951 style 7.62mm Pistol 20.200 500 4 45 ° ± 5 ° 169 40 45 ° ± 5 ° 169 6.35mm Pistol 20.200 500 4 45 ° ± 5 ° 169 40 45 ° ± 5 ° 169

Table B.1 (continued)

9mm

Pistol

20.200 500 5 45 ° ± 5 ° 169 40 45 ° ± 5 ° 169 1953 style 7.62mm Rifle ammunition 10.200 500 3 45 ° ± 5 ° 169 25 45 ° ± 5 ° 169 1956 style 7.62mm Rifle ammunition 12.5.200 500 3 45 ° ± 5 ° 169 25 45 ° ± 5 ° 169 11.43mm Pistol 15.63.200 500 5 45 ° ± 5 ° 169 40 45 ° ± 5 ° 169

Table B.1 (continued)

5.6mm

Sports bullet

20.200 500 3 45 ° ± 5 ° 169 40 45 ° ± 5 ° 169 5.8mm Pistol 20.200 500 3 45 ° ± 5 ° 169 40 45 ° ± 5 ° 169 5.8mm Rifle ammunition 20.200 500 3 45 ° ± 5 ° 169 40 45 ° ± 5 ° 169

Note 1. The warhead is wiped clean, and the characteristics are obvious.

Note 2. The parameters and lighting are accurate and the file name is correct.