A gunman who killed four people at a hospital in Tulsa, Oklahoma, on Wednesday targeted a doctor who had treated him and bought the AR-15-style rifle used in the shooting on the day of the attack, police said.
Michael Louis was armed with a rifle, which he had purchased at 2 p.m. Wednesday, and a handgun when he went to St. Francis Hospital shortly before 5 p.m., officials said.
He opened fire inside the Natalie Building, killing Dr. Preston Phillips, Dr. Stephanie Husen, receptionist Amanda Glenn and a patient, William Love, police said at a news conference Thursday.
Tulsa Police Chief Wendell Franklin said the shooter was a patient of Phillips and underwent back surgery May 19.
The shooter was released May 24 and repeatedly complained about being in pain in the days afterward. On Tuesday, the shooter received additional treatment at the hospital but still complained of pain, Franklin said.
Franklin said the shooter "blamed" Phillips for his pain.
Hours before the killings, the shooter bought an AR-15-style rifle from a gun store. Days before that, he had bought a semi-automatic pistol from a pawnshop, Franklin said.
He said the shooter had a letter with him "which made it clear that he came in with the intent to kill Dr. Phillips and anyone who got in his way."
"He blamed Dr. Phillips for the ongoing pain following the surgery," he said.
The shooting began around 4:52 p.m. on the second floor of the five-story building. A doctor was on a video call with someone and told the person to call 911 to report shots fired, Franklin said. Police got the first report at 4:53 and were on the scene three minutes later.
Franklin said the shooter parked in the parking garage and entered through a second-floor door. As soon as he walked in, “he began firing at anyone that was in his way,” Franklin said.
The shooter died from an apparent self-inflicted gunshot wound as officers were making their way to the second floor. Either before the chaos or during it, the shooter called his wife, who alerted authorities, Franklin said.
Franklin said Phillips was found dead in an examination room. Other people were wounded; a hospital official did not say how many or whether their injuries were from gunshots. The wounded have been treated and released, the hospital official said.
Vice President Kamala Harris said Thursday that "common-sense gun safety laws" need to be passed.
"No more excuses. Thoughts and prayers are important, but not enough. We need Congress to act," she said at an event Thursday.
The shooting follows killings in Buffalo, New York; Uvalde, Texas; and New Orleans. A wave of violence also hit several cities over the Memorial Day weekend, leaving at least 156 people dead and 412 injured from 5 p.m. ET Friday to 5 a.m. Tuesday, according to a preliminary count by the Gun Violence Archive.