The commanders of Sgt. Bowe Bergdahl's platoon, company and battalion testified Thursday at a hearing to determine if he should face a court-martial for leaving his post in Afghanistan six years ago, and each stressed that the ensuing search put his fellow soldiers in danger.

Attorneys for Bergdahl, who is charged with desertion and misbehavior before the enemy, will get to present their own evidence and call witnesses on Friday. His lead attorney, Eugene Fidell, said after Thursday's proceedings that he would call four witnesses, though he declined to say if Bergdahl would be one of them.

"Tomorrow it's our turn at bat," Fidell said.

On Thursday, it was military prosecutors who got to make their case against Bergdahl, and they focused on trying to substantiate the misbehavior charge, which carries a possible life sentence and which would require them to prove that Bergdahl's actions put other soldiers in harm's way.

Capt. John Billings, who led Bergdahl's platoon, described the 45-day search for the Idaho native as grueling, saying soldiers got little food or sleep and endured temperatures in the high-90s.

"Physically, mentally I was defeated," Billings said, adding that he felt like he had "failed" his men.

His company commander, Maj. Silvino Silvino, said some of the thousands of soldiers who took part in the search were angry about it because they felt Bergdahl had deserted.

"I would tell them we are doing what we are doing because he is our brother," Silvino testified.

Finally, Bergdahl's battalion commander, Col. Clinton Baker, said that although no soldiers died as part of the search, there was a spike in improvised explosive device attacks because soldiers were going to places they ordinarily wouldn't have gone. He also said he had to put counter-insurgency efforts on hold due to the search and that it hurt partnerships with the Afghan government and Afghan forces.

Bergdahl spent five years as a Taliban captive until he was exchanged last year for five Taliban commanders who were being held at the U.S. detention center at Guantanamo Bay, Cuba. The prisoner swap was sharply criticized by many Republicans and some Democrats, who said it was politically motivated and counter to the U.S. policy against negotiating with terrorists.

Bergdahl spent much of Thursday's hearing taking notes and conferring with his attorneys. Wearing his blue and black dress uniform, he answered "Yes sir, I do," when asked whether he understood the charges by the officer presiding over the hearing.

Before disappearing, Bergdahl had expressed opposition to the war in general and misgivings about his own role in it. Military prosecutor Maj. Margaret Kurz said Thursday that Bergdahl had actually been planning for weeks to abandon the post and had emailed friends and family about his plans beforehand.

"Under the cover of darkness, he snuck off the post," Kurz told the courtroom.

Legal experts said they expected Bergdahl's lawyers to argue that he suffered enough during his years in captivity. After the hearing wrapped up for the day, Fidell repeated his call for the military to make public Bergdahl's interview with military investigators after the prisoner exchange, saying it would help counteract the negative publicity Bergdahl has faced. He declined to discuss his strategy or to say whether Bergdahl's mental health history would play a role.

Under questioning by one of Bergdahl's attorneys Thursday, both Billings and Silvino said Bergdahl had been a model soldier until he disappeared. Both also said they weren't aware of Bergdahl's mental health history, including his psychological discharge from the U.S. Coast Guard and that an Army psychiatric board had concluded that Bergdahl possessed "severe mental defect."

If Bergdahl is eventually convicted of the misbehavior charge, he could face up to life in a military prison. He could also be dishonorably discharged, reduced in rank and made to forfeit all pay.

The Article 32 hearing will result in a report that will be forwarded to Gen. Robert Abrams, the commanding general of U.S. Army Forces Command. Abrams will decide whether the case should be referred to a court-martial or is resolved in another manner.