Cambridge police are under fire after video surfaced showing officers tackling an unarmed black Harvard student, then punching him multiple times as he was pinned to the ground. Selorm Ohene, a 21-year-old math student, was standing naked on a median in the middle of Massachusetts Ave. around 9pm Friday night; police say his friends reported he may have taken a hallucinogenic drug. Video of the incident (see an AP clip) shows officers surrounding Ohene, then one officer tackling him as he moves toward the officers. Once on the ground, Ohene can be heard crying out "Help me, Jesus"; police have acknowledged he was punched by an officer five times. They say the use of force was justified, but an internal investigation has been launched after the resulting outcry, the New York Times reports. The latest: