A $1,000 reward offer is from private citizens, not from the police department, but the police have also opened an investigation into now-infamous fellow who doused water on an unhoused women as she slept.

You’ve probably seen the viral video by now, or at least an angry social media post or two about it — some mean-spirited individual dumps a bucket of water on a sleeping homeless woman from atop a brick building at 20th and Bryant Streets. The footage was taken last Saturday afternoon at about 2:30 p.m. (neighbors say it wasn’t the first time he’d done this), by Monday night the video was posted on NBC Bay Area, and over the week the story would be picked up by the Guardian, USA Today, and the New York Post, among other national publications.

Yet even with all this publicity, we still don’t know the identity of the notorious water-dumper. But SFGate reports that the SFPD has opened an investigation into the matter.

"We are asking for the public's assistance in identifying any parties involved so we can move forward with the investigation," SFPD spokesperson Joseph Tomlinson told the Chronicle. According to NBC Bay Area, the culprit could be charged with misdemeanor battery.

KPIX’s Joe Vazquez spoke to a man who works in the building in question on Wednesday. “Probably there’s some people from the place next door were up there doing some work on the roof,” he said. “Nobody else has access to it.”

A KPIX follow-up report has workers and the landlord saying that there were no workers on the roof Sunday. This may be a red herring, though, as screenshots of the (now-deleted) original tweet say the incident occurred Saturday, not Sunday.

Prosecuting this guy on a misdemeanor charge would require the victim filing a report, and that may indeed have already happened. The police have made a statement, and KPIX reported that the Coalition on Homelessness has offered the woman legal and supportive assistance.

For those of you amateur sleuths out there, the perp caught on video appears to be a bald man — and I know it’s the day of the day of the Trans March and I shouldn’t be just gender-assuming on people, but still — and more importantly, one who has access to the roof at the 20th and Bryant Street building. If you have any information, the SFPD Tip Line is 415-575-4444.

Related: John Waters On SF's Homeless: 'Every City Now Is Just Rich People and Very Poor People' [SFist]