Here's something usually thought of in rather apocalyptic terms such as the inadvertent or intentional release of an unstoppable plague with near 100% fatality, or worse yet, an organism with 100% fatality and an appetite for anything organic which results in the entire planetary biosphere being reduced to "gray goo". Here's an example which while not as broad spread, is about as disgusting; body lice.
The obvious solution would be to pick this fellow up, de-louse him, find out where he's been living and disinfect that, then turn him loose with the requirement that he wear a Hartz Flea and Tick collar for the next 6 months.
This being Berkley, there's always the chance that he's a student or perhaps one of the faculty, but that's a chance the public health people will have to take. Killing that many lice might bring accusations of genocide.