To Catch a Thief...

Or in this case, not a thief, but the main culprit, and instigator of the crime. Let's view the evidence.
Exhibit A:

Exhibit B:
Exhibit C:I think judging from the photographic evidence, we can deduce that Exhibits A&B, while seemingly caught red-handed (or white-faced), probably did not dump the offending carcinogen
on themselves willingly. Note Exhibit C. Her lack of death-causing powder leads us to believe that she may, in fact, be our criminal.