re: What can DNA prove in this case?

I was wondering this myself. It's not like you are trying to prove or disprove JJ being on premises at all. We know he was at shady's. so there is some DNA somewhere. Unless JJ has a bloody hand and they want to match it to the kids shirt (doubtful) then the means for DNA testing are absurd.

THIS WAS A GOD DAMN BAR FIGHT. We aren't tracking down a f'n serial killer. What a waste of my tax dollars.