About a week before Christmas in 2015, Michael Gallagher lived under the delusion that bedbugs infested his 89-year-old mother's Minneapolis apartment. The only solution to avoid what he believed was a fast-approaching eviction, he would later tell authorities, was to "send her to heaven."

So he killed Patricia Gallagher by beating, smothering and suffocating her at the apartment.

Now he wants her life insurance money.

Normally, that would never happen. Under a 41-year-old Minnesota law informally called the "slayer statute," surviving heirs who "feloniously and intentionally kill" someone are not entitled to death benefits. Any money or property has to go to another survivor.

But this is not an ordinary case. In July, a judge found Gallagher, 63, not guilty of murder by reason of mental illness. He since has been committed to the Minnesota Security Hospital in St. Peter. Reached by phone on Monday, Gallagher said he wanted the money to "help out with expenses after my mother's death."

Although there's no doubt Gallagher killed his mother, he was not convicted in her death.

"Given the fact that he was adjudicated not guilty, that does leave the door open for him to make the claim," said Jim Reichert, who represented Gallagher during his criminal case.

Gallagher's mother, Patricia, listed her son as the primary beneficiary of her life insurance policy for about $3,600. But Horace Mann, the insurance company that holds the policy, filed a lawsuit against Gallagher last week in Hennepin County District Court in hopes of blocking his claim.

"This is a very interesting case," said Joseph Flanders, an Eagan-based attorney who specializes in family and estate law.

Flanders said he could find no cases in Minnesota that were similar to Gallagher's since the 1950s. "This case may very well be settled. However, I would guess that the insurance company and their attorneys may want a ruling on a case like this from a judge or jury."

A specific ruling could set the ground rules for future cases, Flanders said.

In its court filing, Horace Mann's attorney, William Hart, said it is clear under Minnesota law that had Gallagher been convicted of the murder he would not be entitled to any of his mother's money.

"After diligently researching the issue," Hart wrote, Horace Mann could find no judicial precedent of what to do in a case like Gallagher's.

So Horace Mann is asking the court to decide what to do with the money. If Gallagher doesn't get the money, Horace Mann said Gallagher's mother listed two brothers as contingent beneficiaries. They could not be reached for comment.

Gallagher has had problems with mental illness since at least 1991, according to court records, when he was hospitalized at the University of Minnesota and treated with shock therapy.

In the weeks before he killed his mother, Gallagher, a former attorney, became delusional and frantic. He attempted suicide. He became obsessed with the idea that his mother's apartment was infested with bedbugs. A landlord had the apartment inspected and found no evidence of the pests, but Gallagher's delusions persisted.

He took the matter into his own hands, using pesticides that he later believed contaminated the city's water supply. After writing a letter of complaint to his mother's landlord about the bedbugs, Gallagher thought she would be evicted. He feared she wouldn't be able to find another place to live. Desperate to help her, he believed there was only one thing left to do.

"I guess I had it in the back of my mind to kill her to spare her the pain of eviction," he told a psychological examiner during an evaluation after he had been charged with murder. "It was an impossible situation. There was no way out, so I was going to send her to heaven and spare her the problems of the impossible situations we were in."

The evaluation prompted Judge Fred Karasov to rule that Gallagher was unable to understand his actions were wrong.

"He believed that his problems were unsolvable and believed that killing his mother was an act of kindness that would end her suffering," he wrote in his ruling.

Gallagher said this week that he was not aware of the lawsuit filed by the insurance company.

"I thought I had a chance of prevailing," he said. "I didn't think it would be this much of a big deal."