The Louisville gunman's parents say he shouldn't have been able to buy the AR-15 he got 'in 40 minutes' days before the shooting

• The Louisville gunman's parents told the "Today" show he shouldn't have been able to purchase a gun.
• They said their son had been struggling with his mental health in the year before the attack.

The parents of the Louisville gunman who killed five people at a bank earlier this month said their son should have never been able to purchase the AR-15 he got "in 40 minutes" just days before the shooting.

In an interview with Savannah Guthrie, Todd and Lisa Sturgeon, parents of the 25-year-old shooter, said their son had been in treatment for mental health issues in the weeks leading up to the incident.

They said, because of his mental state, he should not have been able to purchase a gun with such ease.

"We know that Connor was seeing two mental health professionals and that he was able to walk in," Todd Sturgeon said on the "Today" show. "From what we have been told is that he walked in ... and walked out with a weapon and ammunition in 40 minutes."

"Because of his mental condition, he should not have been able to purchase the gun," Lisa Sturgeon added. "If there had been a delay or something of that nature, that would have been helpful."

The Sturgeons told Guthrie their son had been struggling with his mental health for the last year and had experienced panic attacks, and anxiety, and had attempted suicide. They said he had been seeing a psychiatrist, and a counselor, and was taking medication for his condition.

They told Guthrie things seemed to have "settled," but six days before the shooting, he called his mother to tell her he had a panic attack, didn't know the cause, and wanted to take off work for a while.

His mother said she set up an appointment with the psychiatrist. She added that the fact that he could have been suicidal was "inconceivable" to her because he was so willing to talk to her about what he was going through.

"We thought he was coming out of the crisis," Lisa Sturgeon told Guthrie.

Research shows that "the large majority of people with serious mental illnesses are never violent" and that gun violence issues in America are not necessarily caused by people with mental illnesses. Rather, studies have shown that access to guns is the "primary culprit" of gun violence.

Anyone over the age of 18 can buy an AR-15 in Kentucky

The Sturgeons last saw their son on Easter Sunday and said that everything seemed normal that day. They said they had no idea he had purchased a gun five days earlier.

Lisa Sturgeon said she was "stunned" when she got a phone call from her son's roommate the following day telling her what was going on.

"Where did he get a gun? We don't have guns," she told Guthrie she recalled thinking.

Police said the 25-year-old was able to purchase the gun legally, according to CBS, and The New York Times reported that he purchased the weapon at a local dealership. His parents told Guthrie he was able to purchase a gun and ammunition that day for $600.

In Kentucky, anyone over the age of 21 can legally purchase a gun, and anyone who is at least 18 can buy an AR-15, local ABC outlet WHAS 11 reported.

The Sturgeons believe something should be done about access to guns in America and that in their case, the issue of guns and mental health are intrinsically linked. They admitted they have no idea what the cause for their son's actions was.

"It would have been bad enough if we had just lost our son. But for him to take others with him is just, it's beyond what we taught him, the way we live," Lisa Sturgeon told Guthrie. "We are always saying 'do no harm.' He didn't do that."

To the families of those who were killed, she offered a message: "We are so sorry. We are heartbroken. We wish we could undo it, but we know we can't."

The family of victim Joshua Barrick told the "Today" show that "he did nothing to deserve this, he simply went to work one day just like all of us do. The fact that anyone can walk in and buy a semiautomatic weapon, its only purpose being to kill many in seconds, is simply wrong."

Their statement continued: "Enough is enough. Inaction is not an option. We deserve to be safe in our communities — whether that be at the bank, the grocery store, our schools, or anywhere else. We are simply heartbroken, this didn't have to happen."