Expert: Dr.Paul Skett - 7/24/2008

Question
We are enquiring in regard to whether or not there is any test which can differentiate two blood samples from the same person. We have a case where a females blood is found on clothing. The owner of the clothing states the blood was deposited a week prior to another incident where more blood was found. On the second occasion she was menstruating (it is not menstrual blood though). Can you test for estrogen or other hormones levels to distinguish samples over cycle ?

Answer
Hi, John,

Thanks for your question - sorry about delay in answering - family emergency took me away from my office for a few days.

If the blood was fresh, an analysis of hormone content would certainly distinguish blood from different times in the menstrual cycle but these hormones are fairly labile and will not survive well in their native state in deposited blood for any appreciable length of time.

Sorry this does not help you a great deal.

Best wishes,

Paul