Forensics Bloodstains Activity

  • Read the article and answer the questions.

“Putting It All Together: A Hypothetical Case”

Joe and Bill have a serious disagreement, and the two men reach a point of true hatred for one another………???

After photographers take pictures of the scene and forensic pathology technicians remove the body, the crime scene investigator examines each and every piece of evidence available to him. Here’s what he finds and where he finds it:

The entryway: High velocity blood spattering from the gunshot to Bill’s arm is on the entry wall and the front doorjamb. Later DNA analysis reveals that this blood matches a sample obtained from Bill. The blow to Joe’s face causes bleeding from his nose and mouth, and blood falls to the floor, producing circular stains. Joe also expirates blood in a fine mist over the wall, the floor, and Bill.

The living room and hallway: Joe continues to expirate a mist of blood as he runs. The spray is found on the carpet, walls, and furniture he passes on his retreat toward his bedroom. He also continues to bleed from his facial wounds. However, the drops that reach the floor no longer leave circular stains because he’s now on the move. The stains become oblong and have spikes or projections pointed along his line of retreat. As Bill continues to strike Joe in the head, medium-velocity impact spatters radiate in all directions. Some reach the floor, and others pepper the wall, the furniture, and Bill. The directionality and impact angle of the drops show that the blood source (Joe’s head) was five feet to six feet above the floor and moving toward the bedroom. At the end of the hallway where Joe collapses, the point of origin analysis shows that the blood source is less than three feet off the floor.

The bedroom: The carpet shows dripped and expirated mist patterns, but they are less clear because of the texture of the carpet. The same is true for the continued impact spatter from Joe’s blows. The bed, wall, and nightstand show medium-velocity impact and expirated spatter as Bill continues his assault and Joe breathes his last breaths. Investigators find the expirated pattern only in the direction Joe’s head is turned, although the impact spatters occur in all directions. Investigators find a void area where Bill stands over the fallen Joe and delivers his final blows.

The escape route: Investigators find bloody shoe prints leading back down the hallway, through the kitchen, and out the back door. Low-velocity spatter with projections indicating movement toward the back door show where blood dripped from Bill’s hands and the pipe during his escape.


You are the criminalist who worked on the case. You have been summoned to testify at the trial on the bloodstain evidence. Explain to the judge and jurors how you reconstructed the scene and determined the sequence of events based on the bloodstain evidence.

Sample Solution