This little-known nugget was buried deep within the bowels of TMZ's website:

Turns out, Chris Rock was approached by Hollywood PD's forensics unit, immediately following the Oscars ceremony. Crime scene tape was unrolled around him. Techs swabbed the insides of his cheeks, and also dusted the outsides of his cheeks.

DNA results were inconclusive, but the dustings provided ample evidence of fresh prints...