A serial sexual predator is on the loose in South Philadelphia, and police say he assaulted four women in a week -- including two on the same night -- this month.



Police on Wednesday released surveillance video showing part of one of the assaults and the attacker in hopes that the public may be able to identify him and help get him off the street.



The black-and-white video, which lasts about 30 seconds, shows the man riding up behind a woman on a bicycle, reaching out and touching her inappropriately. Police say that assault occurred on Aug. 13 shortly after midnight as the 27-year-old victim walked down 8th Street near Fitzwater, in Bella Vista.

The woman screamed, and the assailant rode away on his bicycle.



Police said within about two and a half hours of that attack, the suspect was at it again, this time targeting a 39-year-old woman as she got out of her car and walked home on 13th Street between McKean Street and Snyder Avenue.



The same man is also suspected in two other sexual assaults that occurred elsewhere in South Philadelphia earlier the same week. In the first assault, police say the man approached a 24-year-old woman walking on 15th Street near Moore about 1 a.m. on Aug. 6. He committed that assault in the same way as the one in the released video, approaching his victim from behind while riding a bicycle, then touching her inappropriately and continuing on to flee when she began yelling.



A few days later, police said, the same man is believed to have struck again. In that assault, a 42-year-old woman was walking along Lombard Street between 9th and 10th when police say a man approached her from behind on a bike, touched her inappropriately and then fled west on Lombard.