Salaam,
Can anyone tell me whether DNA may be used in Islamic law as evidence to apprehend criminals? Or can it be used to prove that a person is not guilty?

With regards

salam brother...
allah {swt} gave us a mind to distinguish bettween the right and wrong.
i mean if a person helps others by telling them who killed who allah shall reward
him/her becuase if you have the abilities or the facilities to find out who killed who
then why not find out and inform the others and by doing that you save innocent people.DNA can be used to figure out such things.
just to let you know this is not from me i have asked a religious man that has studied islam and the halal and haram in islam.
and if your not convinced just ask another person or if you want to be sure

attawfeeq inshallah!
w'salam...