Philadelphia police released surveillance video Thursday night showing a man who allegedly assaulted a woman in Kensington Monday and who may be responsible for the rape and strangulation of others in the area.

The video shows a man in the 1800 block of East Sergeant Street crossing the street and approaching an alley. He is holding what appears to be a white iPod or other music player and wearing a hooded jacket with the hood down. The man, who is black, appears to have bushy hair on the side of his face visible in the video excerpt that police released.

The victim is seen later, in an unreleased portion of the video, staggering from the alley, said Capt. John Darby, commander of the Special Victims Unit.

"Somebody knows this guy," Darby said, urging anybody who recognizes the man in the video to call the Special Victims Unit at 215-685-3263.

The victim, a 33-year-old woman, told detectives she was on Kensington Avenue, walking north from Cumberland to Huntingdon Streets, about 2 a.m. when she was approached by the man, who asked "if she wanted to go on a date," meaning to perform sex for money, Darby said.

The woman declined, claimed that her boyfriend was nearby, and walked away, Darby said. The man followed her on Sergeant into the alley, where he attacked her, Darby said.

"She is strangled, she is punched, hit in the side of the head with a rock, a glancing blow," Darby said. The man tried to attack her with scissors but she wrested them away.

Within hours of her reporting the attack to police, she provided a description that led to the new composite sketch, made public this week, Darby said.

The discovery of the surveillance video, taken from a business in the area, "corroborates her account," Darby said.

The importance of the video, which is not very crisp, is that it shows how the man walks as well as other physical details, Darby said.

Detectives are still looking for surveillance video from the areas around the assaults, Darby said.

The video of Monday's attack is available at http://www.youtube.com/user/PhiladelphiaPolice and at Philly.com.

Darby also said that a man who appeared Thursday morning at the offices of Community Legal Service on North Broad Street who was said to resemble the sketch did not fit the overall description of the suspect.

Contact staff writer Robert Moran at 215-854-5983 or bmoran@phillynews.com.