The murder trial of Eddie Ray Routh continues in Stephenville. The trial has boiled down in the last few days to a series of circumstantial evidence and testimonies, all aiming to answer one question: Should Routh be held responsible for the murders of Chris Kyle and Chad Littlefield?

“At the time of this tragedy, Eddie Routh was insane,” said defense attorney Tim Moore on Friday. “Not only was he suffering from a severe mental disease or defect, not only did he not know his conduct was wrong, he thought he had to take their lives because he was in danger.”

The prosecution and its witnesses, however, paint a very different picture.

“Mental illness does not take away your ability to know right from wrong,” argued prosecutor Alan Nash. Evidence of Routh’s substance abuse – including photos showing meth pipes, marijuana paraphernalia and bottles of alcohol in Routh’s home – has only padded Nash’s insistence that Routh was acting of his own accord on the day of the shootings.

On Monday, the court viewed a video recording of Routh’s interrogation following the murders, in which Routh claimed, “I knew if I didn’t take his soul, he was going take mine next. I’m just tired of playing chess with my life.”

While this statement certainly offers points to the defense, Routh also admitted to his interrogator that he was aware that his actions were wrong, lending credence to Nash’s claim that his mental state would not have inhibited his moral decision-making.

Tuesday was the final day of the prosecution’s case, and Nash brought forth a police officer that had transported Routh to the police station. The officer claimed that Routh’s demeanor changed during the ride. Nash argued that Routh’s bizarre behavior was a ploy from the beginning to set up his defense for the murders.

“I’ve been so paranoid and schizophrenic all day,” Routh said at one point in the recording of his ride in the officer’s car. “I don’t know if I’m insane or what’s going on in the world right now.”

Since Wednesday, Routh’s defense has called multiple witnesses – family, friends and a psychiatrist – who have testified to Routh’s severe mental health issues manifesting themselves before the murders.

The prosecution brought in its own rebuttal witness, a psychologist named Randall Price, who explained to the court that Routh’s regular use of marijuana would have heightened the suspicions brought on by paranoid personality disorder, but that at the end of the day, Routh still knew he was doing something wrong. Price also said that Routh had “paranoid personality disorder” which is not technically considered a mental disorder, and that he believes Routh is faking schizophrenic symptoms.

Depending on the conclusion of Friday’s events, closing arguments could be made as early as Monday, Feb. 23.