The 'triple contrast' method in experimental wound ballistics and backspatter analysis.

Area of Science:

• Forensic Science
• Ballistics
• Biotechnology

Background:

• Backspatter on shooters' hands can indicate self-inflicted gunshot wounds.
• Research on backspatter characteristics (presence, amount, patterns) is limited.
• Identifying the weapon's involvement in head injuries is crucial in casework.

Purpose of the Study:

• To develop and introduce a novel method for experimental backspatter analysis.
• To investigate aspects conditioning backspatter presence, amount, and patterns.
• To enhance forensic casework involving gunshot wounds.

Main Methods:

• Developed the 'triple contrast method' using acrylic paint, barium sulphate, and human blood.
• Generated and tested triple mixtures for DNA quantification and STR typing.
• Simulated close contact shots using ballistic gelatine models covered with silicone.

Main Results:

• All triple mixtures yielded sufficient DNA for full STR profiles and forensic identification.
• Endoscopy revealed colored backspatter with typable DNA inside the weapon barrel.
• Radiographic imaging showed contrasted bullet paths, and paint stained fissures aided wound ballistic analysis.

Conclusions:

• The triple contrast method is effective for experimental backspatter analysis.
• This technique allows for simultaneous optical, radiographic, and DNA analysis of backspatter.
• The method provides valuable data for wound ballistic analysis and forensic investigations.