Tulsa police have identified a recent patient as the gunman accused of a mass shooting at an Oklahoma hospital Wednesday.
Two of the four victims were doctors at the hospital, including one who recently performed back surgery on the attacker, police said during a Thursday news briefing.
The gunman killed four and then himself on the second floor of the Natalie Medical Building at St. Francis Hospital in Tulsa, city police said Wednesday.
The gunman, identified as Michael Louis, underwent surgery with Dr. Preston Phillips on May 19, police said. In the following days and weeks, up to the morning of the shooting, he complained of pain and sought additional treatment.
Investigators later found a note on the scene that authorities said "made it clear" that the gunman intended to "kill Dr. Phillips and anyone who got in his way."
Separately, Tulsa Police Chief Wendell Franklin said Louis' wife also called police, telling them that he contacted her and told her what he'd done.
"He blamed Dr. Phillips for the ongoing pain following the surgery," Franklin said during the briefing.
The other victims were Dr. Stephanie Husen, Amanda Glenn and William Love, Franklin said.
Police arrived on scene three minutes after the initial 911 call, placed by a patient who was in the middle of a remote meeting with a doctor who was inside the facility at the time, Franklin said. As they were announcing themselves and approaching the second story, where the active shooting was underway, responding officers heard a gunshot that they believe Louis inflicted on himself.
"The gunshot was at 4:48 p.m. approximately 39 seconds after the first officers entered the building," Franklin said.
Then they walked in on the carnage. They found the first victim, who later died, on an exam room floor.
"We found the suspect, and we rescued a female who was hiding under a desk at the suspect’s foot," Franklin said. "She was there when the suspect took his life."
She escaped without injury. But nearby, officers found another body, according to authorities. They found yet another near the nurse’s station and Dr. Phillips in another exam room.
Wounded victims, survivors and witnesses were evacuated as police secured the building.
The gunman purchased an AR-15-style rifle the day of the shooting, police said, and a .40-caliber handgun days earlier.
"Louis expressed that he was in pain and was not getting relief," Franklin said. "And that was the circumstance surrounding this entire incident."
This is a breaking news story. Check back for updates.