Louisville police have released body camera footage from Monday's mass shooting.

The footage shows the interaction between the shooter and responding officers, including Nickolas Wilt, who was shot and remains in critical condition.

"You will see he never hesitates," Deputy Chief Paul Humphrey said of Wilt during a press briefing on the footage. "This young man went back in to the line of fire."

Humphrey said the suspect "lied in wait" for officers to respond to the bank shooting.

The officers could not see inside the building on their approach, and the footage conveys the "tension" of the scene, Humphrey said.

Officers and EMS treated victims at the scene of the shooting. The actions of first responders "absolutely saved lives," Humphrey said.

Louisville Mayor Craig Greenberg said authorities plan to release 911 audio of the incident within the next 24 hours.

"We know there are still a lot of unanswered questions," Greenberg said at the briefing. "We will continue to provide information as soon as it is available."

Of the eight people injured in Monday's mass shooting, three remain at the University of Louisville Hospital.

One of those patients, 26-year-old police officer Nickolas Wilt, is still in critical condition, hospital officials said, and the other two patients are stable and in fair condition.

Wilt was shot in the head while running toward the gunfire, according to police. Wilt just graduated from the police academy on March 31.

Wilt was on his fourth shift ever when he rushed the shooter, with his field training officer beside him, said Jackie Gwinn-Villaorel, Louisville’s interim police chief.

The training officer, Cory Galloway, shot and killed the suspect, authorities said, while being grazed by a bullet.

The suspected shooter, 25-year-old Connor Sturgeon, bought the AR-15 legally on April 4 in Louisville, Jackie Gwinn-Villaroel, interim chief of the Louisville Metro Police Department, said at a news conference Tuesday.

Sturgeon was a current employee of the bank where the "targeted" shooting unfolded, she said.

Police said body camera footage from officers who responded to the shooting will be released Tuesday afternoon.

A vigil will be held Wednesday at 5 p.m. at the Muhammad Ali Center, Louisville Mayor Craig Greenberg said.

The mayor noted that, under Kentucky law, the gun used in Monday's mass shooting will one day be auctioned off and back on the street.

He pleaded, "It's time to change this law and let us destroy illegal guns and destroy the guns that have been used to kill our friends and kill our neighbors."

"Five more families have lost a loved one," the mayor said.

"This is happening in America everywhere and will keep happening until we say 'enough' and take meaningful action," he said. "Doing nothing is not a strategy, is not a solution."

The suspect left a note and "texted or called at least one person to let them know he was suicidal and contemplating harm," Rep. Morgan McGarvey, D-Ky., said at Tuesday's news conference.

"But we don't have the tools on the books to deal with someone who is an imminent danger to themselves or to others," he said.

"We can come together at the federal level, working with each other to solve this problem which is impacting all of us in a uniquely American way, and get universal background checks so people who shouldn’t have a gun can't buy one," McGarvey said.

"That is not a political issue, but it becomes one when Kentucky Republicans would rather ban books and pronouns, and then make Kentucky a sanctuary state for weapons," he said.

The alleged gunman in Monday's mass shooting at a Louisville bank was wielding an AR-15 when he was gunned down by police, according to Louisville Mayor Craig Greenberg.

Craig revealed the detail during an interview with CBS News on Tuesday morning.

-ABC News' Victoria Arancio