Bloodstain Pattern Analysis

Bloodstain pattern analysis is the forensic interpretation of blood location, shape, direction, distribution, and absence. 121.极简法医鉴识手册：一切犯罪，皆有痕迹 explains that drops, spatter, cast-off marks, transfer stains, voids, and convergence can help reconstruct parts of an event.

The source uses the Sheppard case to distinguish spatter from transfer and to show how blood evidence can challenge a suspect’s explanation. Its broader forensic frame matters: bloodstain interpretation belongs inside Trace Evidence Forensics and Forensic Science / 法证鉴识, so it should be combined with injury, scene, timing, and procedural evidence rather than treated as a stand-alone narrative.

Key Claims

• Bloodstain form can suggest motion, direction, force, distance, and minimum number of impacts.
• Empty spaces or blocked areas can be meaningful when they show where a body or object interrupted spatter.
• Transfer stains differ from impact spatter and can test claimed contact stories.
• Bloodstain interpretation needs caution because geometry does not by itself prove motive, sequence, or identity.

Connections

• Trace Evidence Forensics - broader physical-trace category.
• Forensic Science / 法证鉴识 - institutional frame.
• Contested Forensic Attribution - caution around overclaiming pattern evidence.
• Evidence Over Testimony - blood evidence can test a suspect narrative.