A Jordanian soldier was convicted Monday of killing three US military trainers at a Jordanian air base last year. He was sentenced to life in prison with hard labor.

The defendant, 1st Sgt. Markeek al-Tuwayha, "pleaded not guilty," and has said he opened fire because he thought the base was coming under attack.

He maintained his innocence as he was being led out of the courtroom.

"I have all the respect for the king," he said, "but I was doing my job."

Read: Jordan: A reliable host for Germany's Bundeswehr?

Family members of the killed soldiers were in the courtroom to hear the verdict

Relatives of two of the dead soldiers sat quietly as the judge announced his ruling in a crowded courtroom.

Subsequently, Charles Lewellen, one of the bereaved fathers, said the verdict "won't take the pain away," but that it proved "what we have been saying all along ... that he murdered our sons."

Despite the conviction some relatives criticized Jordan's handling of the case and are disappointed al-Tuwayha didn't receive the death penalty, saying the maximum sentence in this case, life in prison, was not enough.

The victims were 27-year-old Staff Sgt. Matthew C. Lewellen of Kirksville, Missouri; 30-year-old Staff Sgt. Kevin J. McEnroe of Tucson, Arizona; and 27-year-old Staff Sgt. James F. Moriarty of Kerrville, Texas.

All three were US Army Green Berets. They were killed November 4 when their convoy was waiting in line at the gate to the al-Jafr base in southern Jordan.

Read: Afghan soldier kills three US troops in shooting

Shifting the blame

Jordan initially tried to shift the blame to the US, saying the Americans triggered the shooting by disobeying entry rules, a claim that was later withdrawn.

The trial "confirmed that the deceased US service members followed all established procedures when accessing the base the day of the incident, as we have noted before," according to a statement from the US Embassy in Jordan. "We are reassured to see the perpetrator brought to justice."

A button of slain US Army Sgt. Matthew Lewellen

At the start of the trial, the military court Judge Colonel Mohammed al-Afeef said the defendant had no known ties to jihadist organizations. That left open the question about a possible movie.

The defendant, al-Tuwayha, as well as some other gate guards on duty that night, testified that they heard what might have been a gun shot coming from the direction of the US convey.

Al-Twayha claimed he had opened fire because e feared the base was coming under attack. But the other guards testified that they held their fire because they were unsure of the source.

The defendant maintains that he had "no intention of killing anyone" and had no resentment towards Americans.

But video footage of the shooting, described by the relatives who have seen it, said the shooting lasted six minutes, and shows the defendant reloading his gun and shooting at the Americans, even as they waved their hands and yelled, "We're Americans! We're friendly."

bik/rt (AP, Reuters, AFP, dpa)