LOUISVILLE, Ky. — A "suicidal" gunman legally purchased the high-powered rifle used to kill five co-workers at a Louisville bank less than a week before the deadly attack, officials said Tuesday.

Connor Sturgeon, 25, bought the AR-15-style weapon from an authorized seller, interim Louisville Police Chief Jacquelyn Gwinn-Villaroel told reporters.

"We have also learned that he purchased the weapon used in this tragic incident yesterday on April 4," she said. "He purchased the weapon legally from one of the local dealerships here in Louisville."

Rep. Morgan McGarvey, a Democrat who represents Louisville, revealed that the shooter had sent disturbing text messages signaling he was considering harming himself before Monday's shooting.

"We know he left a note, we know he texted or called at least one person to let them know that he was suicidal and contemplating harm," McGarvey said. "But we don't have the tools on the books to deal with someone who is an imminent danger to themselves or to others."

Police on Monday declined to discuss possible motives or confirm if the shooter left behind writings or had previously displayed any red flag behavior.

Two officers, Cory Galloway and Nickolas Wilt, were shot by Sturgeon, officials said. Galloway was grazed on his left side, while Wilt was shot in the head, police said.

Wilt was a recent academy graduate and on only his fourth shift when he rushed toward the bank alongside his field training officer, Galloway, police said.

Galloway was the officer who killed Sturgeon, police said.

“I am just truly proud of the heroic actions of those two officers,” Gwinn-Villaroel said.

Body camera video released by Louisville police Tuesday shows the two officers approaching the bank at 8:41 a.m. Gunfire can be heard and Galloway can be seen tumbling to the ground before he takes cover behind a planter box and returns fire. The video does not show Wilt getting shot.

Most of the video, which was edited and blurred by the police department, was taken from Galloway’s body camera. It also included a still photo from inside the bank that showed the gunman wearing jeans, sneakers and holding a rifle at his side.

Louisville Police Deputy Chief Paul Humphrey said the gunman had an elevated position behind glass doors that gave him a tactical advantage.

“He could see out where no one could see in,” Humphrey said.

At one point, Galloway can be heard saying the shooter is firing “straight through these windows toward the officer.”

Just before 8:45 a.m., Galloway can be heard saying he believes the gunman is down. Moments later, he can he heard shouting, "get the officer."

“You can see the tension in that video,” Humphrey said. “You can understand the stress those officers are going through. The response wasn’t perfect but it was exactly the response we needed.”

The five victims died of “multiple gunshot wounds” with homicide listed as the manner of death, Jefferson County Coroner’s Office records revealed Tuesday.

Four of the victims — Joshua Barrick, 40; Thomas Elliott, 63; Juliana Farmer, 45; and James Tutt, 64 — died earlier in the day. Deana Eckert, 57, was rushed to the hospital following the shooting barrage and died Monday night.

Eckert’s time of death was listed at 6:24 p.m. and her four co-workers were declared dead by the coroner at 12:30 p.m., the coroner said.

Wilt, 26, was shot in the head and was in critical condition Tuesday at UofL Health, a hospital spokesperson said in a statement. Two others who remained at the hospital were stable, the spokesperson said.

Jason Smith, chief medical officer at University of Louisville Health, thanked the American Red Cross for helping supply his hospital with the 170 units of blood used to treat the victims.

Despite Monday’s assault, Smith said, treating that many gunshot victims at one time wasn’t out of the ordinary.

There have already been 40 people killed by gunshot wounds in Louisville this year, Mayor Craig Greenberg said.

Some of the police officers responding at Old National Bank on Monday had to peel off for another deadly shooting just blocks away at Jefferson Community and Technical College.

"I’m weary," Smith said. "There’s only so many times you can walk into a room and tell someone, 'They’re not coming home tomorrow.' And it just breaks your heart when you hear someone screaming 'mommy' or 'daddy.' It just becomes too hard, day in and day out, to be able to do that."

Maggie Vespa reported from Louisville and David K. Li from New York City.

If you or someone you know is in crisis, call 988 to reach the Suicide and Crisis Lifeline. You can also call the network, previously known as the National Suicide Prevention Lifeline, at 800-273-8255, text HOME to 741741 or visit SpeakingOfSuicide.com/resources for additional resources.

This article was originally published on NBCNews.com