A 63-year-old man with a concealed carry license shot an attempted armed robber Monday evening in the South Chicago neighborhood.

The man was walking with another person at 6:19 p.m. in the 8000 block of South Oglesby when the 16-year-old boy and his three accomplices pulled out weapons and demanded their property, according to Chicago Police. The man then pulled out his own gun and shot the boy in his knee, at which point the other suspects ran off.

The boy’s weapon turned out to be a replica handgun, police said.

He was taken to University of Chicago Medical Center in serious condition, police said. Charges against him were pending Tuesday.

Area South detectives were investigating the shooting.