Three people were killed Monday afternoon in a shooting outside a Target store on Research Boulevard in North Austin, police said. A suspect was detained roughly an hour after the attack, which unfolded as shoppers prepared for the new school year. Austin Police Chief Lisa Davis told reporters that officers were dispatched at about 2:15 p.m. and arrived within four minutes to find the victims in the parking lot. Investigators believe the gunman shot two people, stole one of their vehicles, then shot a third person during his escape. He crashed the first car, hijacked another at a nearby Volkswagen dealership and was apprehended on the city’s south side after officers deployed a Taser. The suspect is described as a 32-year-old white man with a documented mental-health history. Austin-Travis County Emergency Medical Services said a fourth individual was treated at the scene for injuries unrelated to gunfire. Authorities have not disclosed a motive and are withholding the victims’ names pending notification of relatives. The parking-lot crime scene remains sealed while detectives review surveillance footage, and Target has yet to issue a public statement.