A Montreal man convicted of stabbing a police officer at a Flint, Michigan, airport was in debt and saw the attack as a way to become a martyr while benefiting his wife and children financially through a life insurance policy, his attorneys wrote in a Thursday court filing.

Amor Ftouhi's attorneys say he should get 25 years in prison and that he should serve that time in solitary confinement.

However, federal prosecutors say Ftouhi should be sentenced to life in prison for committing an act of terrorism transcending national boundaries and for interfering with airport security. They say he was on a mission to kill as many people as possible and then be killed himself.

Ftouhi was convicted in November on several charges in the June 2017 attack. Witnesses said Ftouhi, who is Muslim, yelled "Allahu akbar" — or "God is great" — while attacking Lt. Jeff Neville, who survived being stabbed in the neck.

Defense attorneys wrote that Ftouhi was depressed about being in debt and being unable to properly support his wife and children after he had moved them from Tunisia to Montreal. He also expected that other officers would have killed him and that his widow could have collected on his life insurance policy, they wrote.

"Mr. Ftouhi believed he had found a 'solution' to his financial and emotional predicament: become a martyr for Allah and earn a place in Paradise for him and his family as his reward," they wrote in the memorandum. "Mr. Ftouhi truly believed this was the creative answer to all of his problems both in the present and in the afterlife."

The filing did not list any of Ftouhi's debts and the attorneys declined to comment when reached by phone.

In his filing, U.S. Attorney Matthew Schneider dismissed the defense attorneys' characterization of Ftouhi's attack as a one-time event and a product of his depression and hopelessness.

"Ftouhi may have been unsatisfied with his life but he tried to kill Jeff Neville and intended to kill countless more because he dreamed of being a mujahedeen — a warrior," Schneider asserted. "He yearned to be revered and killing was the way to achieve that. Life imprisonment is the only just sentence for this crime and the only way to ensure the public's safety in the future. The court should impose that sentence."

Investigators have said Ftouhi intended to stab Neville, take his gun and start shooting people at Flint Bishop Airport. He legally drove into the U.S. at Champlain, New York, and arrived in Flint five days later. He tried but failed to buy a gun at a gun show and instead bought a large knife.

"His plan was never to become an indiscriminate killer, attempting to create a mass casualty situation, nor was he trying to be a member of any radical Islamic group," his lawyers wrote. "Mr. Ftouhi most certainly believed he would have been killed on June 21, 2017, and when he wasn't killed, he was very upset."

Ftouhi's lawyers didn't offer an opening statement at trial and didn't call any witnesses. In her closing argument, attorney Joan Morgan said Ftouhi was unstable and believed it would be easier to be killed by police in the U.S. than in Canada.

"Mr. Ftouhi believed he needed to be killed as a 'soldier of Allah' by a uniformed enemy of Muslims in order to solve his problems of debt, to enter Paradise, and to end his life," his attorneys wrote in the memorandum. "He did not believe Allah would accept that an armed Canadian officer was an enemy of Muslims, but he believed an armed United States government official would be acceptable to Allah, given his perceived view of U.S. involvement in the Middle East."