An Olney man is in custody in connection to a robbery in Old City, and police are crediting an anonymous tip for the arrest.

Keith Richardson, 19, of Champlost Street near A, is charged with attempted murder, robbery and related charges in connection to a robbery last month on Sansom Street near 7th in Jewelers' Row.

Surveillance footage from the robbery shows four males, one of whom is believed to be Richardson, following a 23-year-old man as he walks down Sansom in the early hours of Nov. 17. As the man turns to enter a building, he's assaulted from behind by one of the suspects and knocked to the ground.

While the victim lies prone, the suspects steal his iPhone and flee west on Sansom before entering a late model Pontiac Grand Prix.

The tip leading to Richardson's arrest today came shortly after the footage was released online, police said.