ORLAND PARK, Ill — Authorities are seeking a man suspected of fatally shooting a teenager and wounding a bystander at a suburban Chicago mall.

Orland Park police say the suspect and the victim were involved in "an altercation" before the Monday shooting at Orland Square Mall .

Police say the suspect pulled a handgun, fired multiple times and fled the mall, about 20 miles (32 kilometers) southwest of Chicago.

The victim was identified as 18-year-old Javon Britten of Richton Park. He collapsed outside a clothing store and was pronounced dead at a hospital.

Police say the suspect is believed to be 20 years old and likely knew Britten.

Deputy Police Chief Joseph Mitchell says a bystander suffered a graze wound to the leg. Mitchell calls the shooting an "isolated incident."

Mitchell says security video showed a male shooter fleeing the mall but it's unclear if he continued on foot or got into a vehicle. Mitchell calls the shooting an "isolated incident," saying video shows the two people involved knew each other and that the victim was "targeted."

Police departments from several neighboring towns, as well as the FBI and ATF responded to the mall about 20 miles (32.2 kilometers) southwest of Chicago