A University of California police officer drew his gun and pointed it at students protesting meeting of the UC regents this morning, and the UC San Francisco police chief’s explanation as to why doesn’t seem to hold water.

According to the San Francisco Chronicle, UCSF police chief Pamela Roskowski told a press conference today that the officer drew his weapon after a protester took his baton and hit him on the head with it, but that claim appears to be contradicted by a video recording of the incident.

In the video, posted on the Chronicle‘s website, the officer lunges into a crowd which is surging toward him. With his baton held in both hands in front of him, he tussles briefly with one protester. For most of the scuffle, which lasts for less than five seconds, the baton is visible in his possession. As he breaks away from the protester he is clutching the baton in his left hand, and he only