SAN DIEGO -- A 25-year-old man was in custody Monday on suspicion of pulling a gun on clerks at a North Park pharmacy on three occasions and stealing prescription medications, including the painkiller OxyContin.

Derek Franklin Denega of San Diego allegedly committed the armed robberies at the Walgreens store in the 3200 block of University Avenue on May 26, July 21 and Aug. 10.

Surveillance cameras captured images of the thief, a slim man clad in a hooded jacket with the head covering up or a long-sleeved pullover shirt and a white baseball cap, according to police.

On Friday evening, a patrol officer who had seen the photos spotted Denega in the 4000 block of Ohio Street, four blocks from the drugstore, and arrested him without incident, police said.