Army Sgt. Bowe Bergdahl: Who is he?

The Army soldier who was held captive in Afghanistan after leaving his station pleaded guilty last week to desertion and misbehavior before the enemy.

Army Sgt. Bowe Bergdahl's sentencing hearing begins on Monday with dramatic testimonies expected from soldiers who were wounded while they searched for the missing Bergdahl. He was held captive by the Taliban for five years after he deserted his post.

He faces up to life in prison for his charges.

Bergdahl’s story has left the nation debating for eight years about whether he is a hero or traitor, as well as the importance of the long held American commitment not to leave troops behind. Former President Barack Obama defended swapping prisoners at Guantanamo Bay for Bergdahl’s release in 2014 while President Donald Trump said Bergdahl should “face the death penalty.”

Why is Bergdahl on trial?

Then 23, Bergdahl went missing from his remote infantry post near the Pakistan border in June 2009. His disappearance launched a massive search operation.

Bergdahl was quickly captured by the Taliban after leaving his post. The U.S. tracked him for several years before successfully negotiating his release in 2014. The U.S. does not "leave our men or women in uniform behind," Obama said, regardless of how Bergdahl came to be captured.

BERGDAHL BEARS SOME RESPONSIBILITY FOR RISKY MISSIONS TO FIND HIM, JUDGE SAYS

U.S. President Barack Obama (R) watches as Jami Bergdahl (L) and Bob Bergdahl talk about the release of their son, prisoner of war U.S. Army Sergeant Bowe Bergdahl, during a statement in the Rose Garden at the White House in Washington May 31, 2014. Obama, flanked by the parents of Army Sergeant Bowe Bergdahl, a U.S. soldier who is being released after being held for nearly five years by the Taliban, said in the White House Rose Garden on Saturday that the United States has an "ironclad commitment" to bring home its prisoners of war. REUTERS/Jonathan Ernst    (UNITED STATES - Tags: POLITICS MILITARY) - GM1EA610J6201

Army Sgt. Bowe Bergdahl pleaded guilty to desertion and misbehavior before the enemy.  (Reuters/Jonathan Ernst)

Bergdahl has said that he left his post and intended to alert people about problems he perceived within his unit. Investigators said Bergdahl suffered from schizotypal personality disorder when he left his post.

The Army charged him with desertion and misbehavior before the enemy in 2015.

What could happen?

Bergdahl faces up to five years in prison on the desertion charge. But he could also be sentenced to life in prison for the misbehavior charge.

It’s unclear if prosecutors and the defense reached some sort of agreement ahead of sentencing about Bergdahl’s fate. Bergdahl’s lawyer declined to comment when contacted by Fox News.

What has Trump said?

Trump has been a vocal critic of Bergdahl and the Obama administration’s decision to exchange five prisoners in Guantanamo Bay for his release in May 2014.

BERGDAHL HAD PSYCHIATRIC DISORDER WHEN HE LEFT POST, DOCUMENTS SAY

"We're tired of Sgt. Bergdahl, who's a traitor, a no-good traitor, who should have been executed," Trump said at a Las Vegas rally in 2015.

On Twitter, Trump has also said Bergdahl should face the death penalty and repeatedly referred to him as a “traitor.”

Is there anything else to know about the case?

Bergdahl elected to be tried by a judge, not a panel of military officers, in August.

The judge will hear testimonies from soldiers who were injured as they searched for Bergdahl after he went missing. One soldier is in a wheelchair and is unable to speak because of a head wound. Another soldier is still unable to use his right hand; and a third soldier suffered a leg wound that ended his career as a Navy SEAL.

Defense attorneys had attempted to get the case thrown out because of Trump’s ardent and harsh criticism of the soldier. But the judge, Army Col. Jeffrey R. Nance, rejected the request.

The Associated Press contributed to this report.

Kaitlyn Schallhorn is a Reporter for Fox News. Follow her on Twitter @K_Schallhorn.