The fathers of two of the three U.S. military trainers killed at a Jordanian air base last year said Wednesday that they have more faith in the kingdom's legal system after attending the trial of the alleged gunman this week.

A Jordanian soldier serving at the base has been charged with murder in the November shootings and is being tried by a local military court. The defendant, 1st Sgt. Marik al-Tuwayha, allegedly opened fire on the Americans' convoy as it waited to enter the base, killing three U.S. Army Green Berets.

But bereaved fathers James Moriarty and Brian McEnroe also expressed concern about testimony from gate guards at the base who said they heard a sound, possibly a pistol shot, from the direction of the convoy before the Americans came under fire.

Close U.S. military ally Jordan had initially suggested that the Americans triggered the shooting by disobeying orders of Jordanian troops at the gate. Jordan later withdrew this claim and King Abdullah II cleared the U.S. troops of any wrongdoing in a letter to their parents.

"I'll probably go to my grave believing it was not a pistol shot," Moriarty, a 70-year-old trial lawyer from Houston, told The Associated Press after Wednesday's court hearing. "The boys wouldn't have done it. It doesn't make any sense. They were professionals, that wouldn't have been the time and place."

Both fathers have watched security camera footage of the shooting shown to them by U.S. law enforcement officials. While the video did not have sound, the men said it also did not indicate that a pistol shot had been heard because a gate guard did not react until the Americans came under fire.

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.

Three gate guards told the court this week that a four-car convoy carrying the U.S. military trainers pulled up at the entrance of the al-Jafr air base in southern Jordan before noon on Nov. 4.

All four vehicles passed through the outer gate of the base. The lead vehicle then passed through the inner gate, leaving three more vehicles between the outer and inner gates.

Guards testified that they heard an apparent pistol shot from the direction of the convoy. They said that under the rules of engagement, they were allowed to return fire, but that they did not do so because they could not locate the exact source of the purported gunshot.

At this point, the defendant was in the guard house next to the inner gate, close to the lead car driven by McEnroe, with Lewellen as a passenger.

Moriarty has said the security camera video showed the defendant opening fire on the convoy. McEnroe and Lewellen were killed instantly. Moriarty's son and another U.S. trainer who survived rushed out of their vehicles, tried to take cover and returned fire, while calling on the shooter to stop, the elder Moriarty said.

A crime scene investigator testified this week that 78 rounds were fired from two M-16 rifles, the weapons used by the Jordanian troops, and 19 rounds from pistols used by the U.S. forces.

The bereaved fathers had initially been critical of Jordan's handling of the case.

However, Moriarty said Wednesday that he believes the court "will render justice."

McEnroe said he initially feared he would observe a "show trial," but that he no longer believes this is the case. "The judge and the assistant judges seem genuine in their desire to resolve this and come to a fair verdict," he said.

Moriarty attended all four sessions this week. McEnroe did not come to court Wednesday, saying that he "just didn't want to relive it again."

The next hearing is set for July 4. The fathers are leaving Jordan on Thursday.

The defendant, who has pleaded "not guilty," faces life in prison if convicted.

McEnroe said the defendant should be given a harsher punishment if found guilty.

"Do I feel that the maximum punishment allowed under Jordanian law for his crime fits the crime? Absolutely not. He should be hung," said McEnroe.