The parents of the 25-year-old gunman who killed five people at a bank in downtown Louisville this month have a message for the families of their son’s victims.

“We are so sorry. We are heartbroken,” Lisa Sturgeon, Connor Sturgeon’s mother, told NBC News’ Savannah Guthrie in an exclusive “TODAY” show interview. “We wish we could undo it, but we know we can’t.”

Read more on this story at NBCNews.com and watch the full interview Thursday on “TODAY” at 7 a.m. ET/6 a.m. CT

Connor Sturgeon was an employee at Old National Bank on East Main Street, where he opened fire with an AR-15-style rifle during a board meeting on April 10, killing five people — including a friend of Kentucky Gov. Andy Beshear — and injuring eight others.

Authorities identified the five who were killed as Josh Barrick, 40; Deana Eckert, 57; Tommy Elliott, 63; Juliana Farmer, 45; and Jim Tutt, 64.

Two of the eight people who were injured were police officers — among them Nikolas Wilt, who is still recovering from a gunshot wound to the head.

Police officers arrived in three minutes, exchanged gunfire with Connor Sturgeon and killed him, interim Police Chief Jacquelyn Gwinn-Villaroel said.

The violence sent shock waves through Louisville and across the U.S., where mass shootings in everyday places have become sickeningly commonplace. The bloodshed in Louisville took place just 14 days after a 28-year-old shot and killed six people at a Christian school in Nashville, Tennessee.

In a statement released the day after the bank shooting, the Sturgeon family said Connor had “mental health challenges” they were working to address. But he showed no signs of violence, they said.

Louisville authorities have released several 911 calls — including one from Lisa Sturgeon. She said her son had a gun and was on his way to the bank. She had gotten a phone call from her son’s roommate, who was concerned.

“I need your help,” Lisa Sturgeon told the 911 operator.

But by the time Lisa Sturgeon placed the call, Connor Sturgeon was already at the bank.

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.