Question

CASE STUDY As a DNA analyst you must sometimes use blood spatter analysis on items of evidence. A crime scene technician collects multiple samples from the crime scene itself and also a lot of evidence from the body. Upon speaking with the detective on the case, you find out that he wants to find the suspect's blood somewhere in the evidence as he thinks he may have been bleeding from a struggle with the victim. One of the items that is submitted is the victim's shirt. As a DNA analyst you will have to select which stains to analyze for a DNA profile. The back of the shirt has two blood stains on it. One has an angle of impact of approximately 15 degrees and one has an angle of impact of approximately 90 degrees. You can pick one stain to run - which one would it be and why?

Answer 1

Analysis of DNA in any of the crime is very important aspect to identify the real criminal from just a suspect. It is one of the very important discovery in the field of science and technology which has helped to capture millions of criminals.

The blood spattered on the back side of the victims shirt indicates that the victim was attacked from behind and that suspect had struggled to get hold of the victim. During the struggle the suspect will get an injury which will splatter his blood to an angle of 15degree as he will try to take the affected area away from the attacker.

As for the angle of blood impact of the victims blood it will be on the 90degree angle as the victim will get the blood directly opposite to the area of the attack.

Hence, in my opinion the blood stain of the suspect would probably be the one at 15degree angle.