Relatives of a Jordanian soldier convicted of killing three American military trainers last year are vouching for his innocence, demanding that his murder conviction be overturned.

Members of the Huwaitat tribe accuse the Jordanian government of "covering up the truth" and say officials are hiding details that should exonerate Maarik al-Tawaiha.

The 39-year-old was convicted in June of killing of three American Special Forces officers - Matthew C Lewellen, 27, Kevin J McEnroe, 30, and James F Moriarty, 27.

The three were part of a CIA programme training members of Syrian opposition groups in Jordan when they were killed at King Faisal Airbase at al-Jafr, in southern Jordan, on November 4.

Sayel Abu Tayeh, a leader of the Huwaitat tribe and a royal court adviser on tribal affairs, said in a statement early this week that Tawaiha followed the rules of engagement as he believed the base was under attack by unknown assailants.

The CIA used the King Faisal Airbase to train Syrian fighters battling the Syrian government of President Bashar al-Assad.

The Tawaiha family's version of events that led to the shooting of the Americans is sharply in contrast with the official account of the incident.

Abu Tayeh, a close relative of Tawaiha, accused key figures in the Jordanian government of a "cover-up" and of using his relative as a "scapegoat" in order to deflect American pressure and cover their own security failure.

"What happened on that day was a mix-up that led to the tragic shooting," he said.

"We are saddened that Americans were killed in that incident, but Maarik was no murderer."

Al Jazeera could not confirm many of Abu Tayeh's claims regarding the current or former Jordanian government officials.

But Al Jazeera has obtained several Jordanian court documents, including Tawaiha's own statement and those of witnesses.

Those witnesses said they heard a gunshot being fired, without specifying by who or from where, which triggered the chain of events that later followed.

They also described a battle between the soldiers defending the base's gate and "unknown assailants" riding in cars approaching the base and shooting at it.

Surviving US soldier's account

A fourth American soldier, whose name is withheld, was with the three slain soldiers.

He survived the attack described a different version of events in a New York Times report last July.

"Gunshots erupted from a guard post, inciting a shoot-out that killed three Americans," the lone American survivor said.

"We kept yelling in English and Arabic, saying we were friends. And he kept shooting," he said. "Eventually, we realised it wasn't an accident."

The Jordanian military and the FBI released a five-minute video last July that shows the convoy of cars driven by the Americans, stopped at the gate, waiting to be let in when the gun battle erupted.

It also shows the American soldiers jumping out of their cars while firing their guns, hiding behind concert barriers, and later waving their hands up in the air to stop the attack.

The video showed Tawaiha charging towards them with his assault rifle trying to kill them.

Father of slain US soldier speaks

However, James R Moriarty, the father of slain soldier James F Moriarty, told Al Jazeera that he understands Tawaiha family's insistence on his innocence because "they were fed the wrong information by the Jordanian government".

On November 4, Reuters news agency quoted an unnamed Jordanian military source saying: "Three US military trainers were shot dead in Jordan when their car failed to stop at the gate of a military base and was fired on by Jordanian security forces."

The Jordanian government later changed its story several times.

"But this does not change the fact that the three American soldiers were killed in cold blood by Maarik," said Moriarty.

He said his son clearly communicated that he was not a threat and even talked to Tawaiha during the shooting, identifying himself as a friend and that they were Americans.

Maarik shot and killed Lewellen and McEnroe at very close range from his position inside the concrete shack.

"My son was deliberately murdered," he said.

He also blamed the other Jordanian soldiers at the base's gate for "doing nothing" to stop the firing.

The US Army report investigating the incident noted that the American soldiers followed procedure as they approached the base.

Multiple attempts to reach Mohamad al-Momani, the Jordan government spokesman, for an official response to the Tawaiha family's accusations were unsuccessful.

The US embassy in Jordan said 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".

"We are reassured to see the perpetrator brought to justice," it said.

Tawaiha's mother has released a video accusing the government of using her son as a "scapegoat".

She said her son was a thorough professional and a loyal soldier who never harboured any "extremist" beliefs that might have led him to kill the US soldiers.

She has appealed to Jordan's King Abdullah to help release her "innocent" son.

COURT DOCUMENT BEARING MAARIK AL-TAWAIHA'S TESTIMONY TO JORDAN INVESTIGATORS, OBTAINED BY AL JAZEERA:

"Two days before the incident, a shooting took place inside the training centre [inside the base] after which we were instructed to respond to any source of firing or shooting without having to wait for orders.

"On the day of the incidence, [He was present inside the concrete shack at the entrance of the base in order to charge the battery of his radio according to witnesses testimony] I heard a shooting, and immediately I loaded my gun and started firing from the window of the shack at the direction of the source of fire.

"I did not have any intention to harm or kill anyone; I was defending my colleagues and the base. Even when I was firing my gun, I was not aiming at any particular person. I was following the rules of engagement, which was to respond to fire with fire. Then, I was surprised by a man wearing civilian clothes pointing his gun at me and shooting me three times.

"I fell to the ground while the firing was still going on. My colleagues participated in the shooting using their rifles and machine guns in defense of the gate of the base. We did not know why the persons who were coming to the base were shooting at its gate.

"Before the incident, neither me nor any of my colleagues had any misunderstanding with the American side. I do not know the reason why they started shooting at the base's gate and the guards.

"The situation [during the shootout] did not tolerate any waiting since the circumstances required us to respond to the source of fire at the minute we hear it.

"I do not hold any unpatriotic thoughts, I am not connected to any [terrorist] group and no one pushed to fire my gun at any person. My only motivation was to apply the rules of engagement as instructed."

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