MADISON, Wis. — A shooting that wounded a disc jockey at a Wisconsin radio station appears to have been a targeted attack against a specific individual, police said Monday.

Sunday's shooting at WORT-FM in Madison wasn't a random attack or an act of violence targeting the media, according to police spokesman David Dexheimer.

Authorities are still looking for the masked gunman who entered the non-commercial radio station around 3 a.m. Sunday and opened fire on three people in one of the studios. One of the three volunteers, a DJ, was wounded. He was treated at a hospital and released. The two others were not injured.

Station officials said the three ran into the adjacent control room before hiding in the music library and calling 911.

Doug Holtz, the station's business director, said they are reviewing security practices.

"We've changed out the codes on all our door locks. And we are reasserting (to staff) to keep those codes private," Holtz said. A security camera at the station's front entry used to monitor visitors is not yet capable of recording and did not capture the intruder, Holtz said.

The shooter entered the station during the transition between the midnight program and 3 a.m. show, station officials said. It was unclear whether the shooter knew the code or held the door open after someone entered the station.

The listener-sponsored station, which broadcasts a variety of music, was off the air following the shooting but returned to broadcasting about six hours later.