Police are asking for the public's help in identifying the person who hit an officer Tuesday at a May Day rally in downtown Los Angeles.
The man hit the female officer in the back of the head with an object first thought to a skateboard.
The officer was wearing a helmet and was not seriously injured, but was taken to the hospital.
Authorities are now saying the object may have been a drum.
Video of the incident--called "Cheap Shot at A Cop"--has already gone viral on the Internet Wednesday.
Watch it in our media gallery.
LAPD Commander Andy Smith has said that whoever hit the officer--who did not fall, but did have a dented helmet--will be arrested.
It will be interesting to see how Occupy LA responds, if that is in fact the case.