I just thought of something: what if the guy who dropped the chlorine was wearing a fursuit, as a disguise? It would be the perfect scheme. You would blend in perfectly at the building for one thing. No one would bat an eye at one costumed weirdo over another. Secondly (assuming no one saw you while you were putting the costume on), even if you got captured on a security camera or in a picture, you could just burn the suit later and you no one would be able to find you. Assuming you make sure to dump the costume carefully, that could be a perfect getaway almost.