DNA Soup

[tcdaniel]

Would mixing different types of human blood produce any changes to the original DNA for detective purposes?

[Q.E.D.]

Didn't you watch the O. J. Simpson trial? Analysis of some of the blood splatter contained one or both of the victim's DNA as well as some of O. J.'s (<--- what do the punctuation police in that other thread have to say about that?) DNA. They could tell that because they can compare known DNA samples to the mixed sample to match up the genetic markers the test picks up.

[Smeghead]

See this (http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=158206) thread. It's basically the same question.