FORT BRAGG, N.C. (Reuters) – Lawyers for U.S. Army Sergeant Bowe Bergdahl will build their case on Tuesday for why he should be spared prison time for walking off his Afghanistan post in June 2009 and endangering the troops who searched for him.

The 31-year-old soldier, a polarizing figure who spent years in captivity and was released in a 2014 Taliban prisoner swap brokered by Democratic President Barack Obama’s administration, took the stand at his sentencing hearing on Monday.

The Idaho native faces up to life in prison after he pleaded guilty on Oct. 16 to desertion and misbehavior before the enemy. He has no plea agreement with prosecutors, leaving his sentence up to Army Colonel Jeffery Nance.

Bergdahl gave nearly two hours of unsworn statements, meaning prosecutors did not get to question him. He discussed his mental health and the torture and neglect he endured after being captured by the Taliban, factors the defense hope will earn him leniency.

“The worst was the constant deterioration of everything — the pain from my body falling apart, the constant internal screams from all the darkness and light and everything I had to deal with,” Bergdahl said at North Carolina’s Fort Bragg.

The military judge ruled on Monday that disparaging comments made by Republican President Donald Trump about Bergdahl had not affected the fairness of the court proceedings.

During last year’s presidential campaign, Trump called Bergdahl “a no-good traitor who should have been executed,” and the defense said the president endorsed such comments in more recent remarks.

Nance said he was not influenced by the statements and would render a just sentence. The judge said, however, he would consider the president’s remarks as a mitigating factor.

The judge also will weigh aggravating evidence presented during the past week by prosecutors.

Multiple service members spoke of the hazardous conditions they faced in the futile search for Bergdahl, who says he deserted his duties to report “critical problems” in his chain of command.

Several soldiers fell ill or were badly injured during hastily organized missions to find him. Master Sergeant Mark Allen, the most critically hurt, suffered a debilitating brain injury that left him unable to speak or walk after being shot in the head in July 2009.