A teenage boy who was shot while robbing a woman at gunpoint Tuesday morning in the South Side Douglas neighborhood is facing charges.

A 25-year-old woman was walking in the 2100 block of South Tan Court about 10:15 a.m. when two teenage boys approached her from behind. One of them was armed with a silver handgun, and they stole her purse, according to Chicago Police.

One of the boys, 17, was taken into custody after a short foot chase with officers in the 100 block of West Cermak, police said. The purse was recovered

The other boy, also 17, was shot by a male citizen who witnessed the robbery, police said. He was taken into custody at Northwestern Memorial Hospital, where he was being treated for a gunshot wound to the buttocks. The handgun used in the robbery was recovered from his property.

Both teens were charged with one felony count of armed robbery with a firearm, police said. The boy who was shot was also charged with one felony count of unlawful use of a weapon.

The citizen who shot the boy has not been identified, police said.