system
Given the following post, respond as if you're commenting on Reddit:
human
If you mixed a bunch of people's blood in a blender, and spilled it all over a crime scene, could they figure out whose DNA was whose?

I'm not implying that a blender could blend DNA or anything, but what problems would this create? Would eat swab give a different result?
gpt
I am a forensic DNA analyst. The result of each swab would give roughly the same result (unless the blending was incredibly short, as there is enough DNA in blood to ensure complete mixing of DNA profiles). Each swab would have all the different DNA. 

While it's technically true that the instruments used would detect each unique DNA sample present in the mixture (the instrument would detect each different allele present in the mixture from whatever genetic markers you used for the DNA profiling). It is not able to separate specific profiles from each other. That would take further analysis of the results. For each extra person you mix with another, the less confident you can be to separate each DNA profile upon analysis. 

Also, it would be very difficult (maybe impossible?) to actually physically separate each person's DNA from the mixture (at least with any technology a common forensic lab possesses).

EDIT: As astazangasta said, good luck trying to prove it in court. Defense attorneys have field days over mixtures.