Bloodstain Pattern Analysis
Bloodstain pattern analysis serves a significant role in answering the question of “what” happened during the commission of a crime. By using methodical and scientific principles, bloodstain pattern analysis helps establish specific events associated with violent crimes. This information will re-create events that support or refute witness statements and will assist the court in determining intent and help the jury to visualize the final moments. Bloodstain pattern analysis can assist in determining the following:
- Location and description of individual stains and patterns
- Mechanism that created the stains
- Direction a blood droplet was traveling
- Area of origin
- Type of object used in attack
- Minimum number of blows
- Presence of a subject at a scene
- Positioning of the victim, suspect and objects during events
- Sequence of events
Proper Documentation of a Bloodstain
Photography is the best way to document any bloodstain patterns, preferably high quality color photographs with scales. Overall images, mid-range images, and close up images of each bloodstain pattern should be taken. Photographs should be taken prior to any alterations or collection of any blood evidence.
What is Needed for Bloodstain Pattern Analysis?
Although, not every case will have each of the items listed below. It is imperative to achieve the most accurate and complete analysis that the submitting agency do their best to obtain the following:
- Brief background information
- Examination of the actual scene (if possible)
- Examination of physical evidence
- Photographs of the crime scene
- Photographs of the physical evidence
- Photographs of the autopsy
- Autopsy report
- Serology report
- Crime scene diagram (s)
- Crime scene investigator’s notes or reports
- Responding officer’s notes or reports
- Emergency medical technicians’ (EMT’s) notes or reports
- Any additional forensic reports