Josh Benson now faces charges in adult court in seven alleged assaults, and police say he was charged with an eighth case Friday.
Since October 10, there have been three attacks during the morning hours, including the rape of a 22-year-old woman on E. Lycoming Street.
The Citizens Crime Commission has put up the $2,500 reward for any information leading to the arrest and conviction of a suspect in the attacks, which occurred during the past three months.
Police are searching for a serial rapist who has attacked four young girls in the streets of Germantown since March.
Police believe the suspect may have victimized other women and are urging anyone who may have been assaulted to come forward.
A judge declared a mistrial on Tuesday after a jury was unable to reach a verdict in a case against alleged Kensington serial rapist Marcos Camacho.
Philadelphia police have released a sketch of a man they think may be a serial rapist. According to police, the same suspect is wanted in connection with two incidents in the northeast.