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

Kentucky is one of 26 U.S. states that allow for permitless carry of firearms for eligible adults.

The Bluegrass State passed a law in 2019 removing the provisions that mandated state gun owners pass a background check if they were going to going to conceal carry their weapon. Under the law, most adults over the age of 21 can purchase and carry a firearm and take them to most places in Kentucky without any license.

Although gun owners can still apply for a gun license, which requires background checks, they are only meant for people who need such permits when traveling out of state.

Aside from federal laws that prohibit gun purchases by people with convicted felonies, there are no Kentucky laws that prohibit gun purchases to state residents who have mental health disorders, violent misdemeanor convictions, domestic abuse-related restraining orders or anyone with substance abuse disorders.

Firearms are still prohibited in several locations in Kentucky. Schools, government buildings, courthouses, police stations and any place that serves alcohol are gun-free locations, according to state law.

Kentucky law does not have any provisions preventing firearms in several locations such as hospitals, houses of worship, sports arenas, casinos, polling places and banks. However, local business owners and public and private colleges are also allowed to prohibit firearms on their properties, but they must have adequate signage on their premises, according to state law.

-ABC News' Ivan Pereira

"There are no words to adequately describe the sadness and devastation that our Old National family is experiencing as we grieve the tragic loss of our team members and pray for the recovery of all those who were injured," Old National Bank CEO Jim Ryan said in a new statement Monday night.

Ryan and other members of the Old National leadership team have been in Louisville much of the day offering support to affected individuals and their families, and they will continue to be on hand to provide support in the days ahead.

"Obviously, this is an incredibly difficult situation, and our entire focus is on making sure that everyone affected has the support and assistance they need," Ryan said. "On behalf of everyone at Old National, I also want to acknowledge and thank Louisville law enforcement, the medical community and state and local officials for their incredible response to this tragedy. And finally, we ask you to please continue to pray for all those affected."

-ABC News' Vera Drymon