At least six American soldiers were killed in the search for Army Sgt. Bowe Bergdahl after he left his unit in Afghanistan. Almost five years later, the Obama administration traded five Gitmo detainees for the release of Bergdahl from Taliban captivity.

One of those killed was 20-year-old Private First Class Matthew Martinek. He died on September 11, 2009 after an IED exploded while he was looking for Bergdahl.

Martinek’s mother Cheryl Brandes and stepfather Ken Luccioni spoke to Bill O’Reilly tonight.

National Security Advisor Susan Rice has stated that Bergdahl served with “honor and distinction.” However, soldiers who served with Bergdahl have come out and said that he deserted his unit.

Luccioni said the Bergdahl should “absolutely” be prosecuted when he returns to the U.S.

“There’s a code of justice that when these young men … and ladies sign up for the armed services they agree to,” he said, adding that there needs to be a full investigation into the soldier’s disappearance.

Luccioni said he understands the Bergdahls’ joy at having their son back. “I have no problem that he’s home. Personally, I have a major problem how we got him. But the fact of the matter is that this man has to be accountable for his actions.”

Brandes said that if her son was a prisoner of war, he would not have wanted there to be a prisoner swap.

“I know that with my son, if he was captured and didn’t go AWOL, I know for sure that he would not want five extremely dangerous terrorists traded for his life. He would give his life because he would be very worried on the consequences that would go forward,” she said.