In scenes with large quantities of blood, what should be tested?

In scenes with large quantities of blood, what should be tested?

• A. Blood from clothes only
• B. Only the suspect blood
• C. Subject and victims blood mixed together in the same pool
• D. Blood from the environment only

Answer: (C)

When there’s a large pool of blood, multiple people can contribute to what’s in that pool. The key idea is to analyze the mixture itself to identify all contributors, not just a single source. Testing only the suspect’s blood or only environmental stains can miss other DNA present in the same pool and lead to incomplete or misleading conclusions. By examining the mixed sample and, if needed, using methods to deconvolute the mixture, you can recover DNA profiles for all individuals represented—such as both the victim and the suspect—within that single pool. This approach ensures you don’t overlook contributors who shared the same blood evidence.

When there’s a large pool of blood, multiple people can contribute to what’s in that pool. The key idea is to analyze the mixture itself to identify all contributors, not just a single source. Testing only the suspect’s blood or only environmental stains can miss other DNA present in the same pool and lead to incomplete or misleading conclusions. By examining the mixed sample and, if needed, using methods to deconvolute the mixture, you can recover DNA profiles for all individuals represented—such as both the victim and the suspect—within that single pool. This approach ensures you don’t overlook contributors who shared the same blood evidence.