STEPHENVILLE, Texas (AP) — Prosecutors in the murder trial of an ex-Marine accused of killing "American Sniper" author Chris Kyle and another man told jurors Tuesday before they began deliberations that they should disregard the insanity defense of the defendant's attorneys.

State District Judge Jason Cashon turned the case over to the North Texas jury around 5:30 p.m. Tuesday after about three hours of closing arguments from both sides. There was no indication how long jurors would be asked to deliberate Tuesday evening.

Eddie Ray Routh, 27, has admitted to the killings of the former Navy SEAL Kyle and his friend, Chad Littlefield, at a gun range in 2013 but pleaded not guilty. His attorneys and family members asserted that he suffers psychotic episodes caused by post-traumatic stress disorder and other factors.

But prosecutors said Tuesday that whatever episodes Routh suffers are self-induced through alcohol and marijuana abuse.

"This defendant has gone to the deep well of excuses for his violent behaviors one too many times," Erath County District Attorney Alan Nash said.

"I am tired of the proposition that if you have mental illness that you can't be held responsible for what you do," Nash continued.

Defense attorneys cited testimony by their experts that Routh was insane when he shot Kyle and Littlefield.

"He was not intoxicated, folks. He was psychotic," defense attorney Warren St. John told jurors, accusing prosecutors of giving them a false impression of Routh's drug use.

Furthermore, there was no evidence to indicate that Kyle would take someone who was intoxicated to a firing range, they said.

Kyle and Littlefield took Routh, who had deployed to Iraq and earthquake-ravaged Haiti, to a shooting range after Routh's mother asked Kyle to help her son cope with PTSD and other personal demons. Interest in the trial has been partially driven by the Oscar-nominated film based on Kyle's life.

Routh's attorneys also pointed to the gunman's use of Kyle's pickup truck after the shooting to purchase tacos at a drive-through window and run assorted errands as evidence of delusional behavior. They called it insanity.

Prosecutors called it cold-bloodedness. They also noted that Routh led police on a high-speed chase before finally surrendering.

"He wasn't one bit sorry for what he did," Nash said. "He knew it was wrong."

Since prosecutors aren't seeking the death penalty, Routh would face an automatic sentence of life in prison without parole if convicted of capital murder. If he's found not guilty by reason of insanity, the state can move to have him committed.

Routh's attorneys pointed out that they needed only a preponderance of evidence for jurors to conclude Routh was insane at the time of the shootings and therefore not guilty, a standard of proof well below what would be required to convict him of capital murder.

But prosecutors also noted that Routh had apologized to Kyle's family — evidence, they said, of a guilty mind.

"This defendant gunned down two men in cold blood, in the back, in our county. Find him guilty," Nash said.