HILO, Hawai'i — A federal court judge has ruled that prison officials did not violate the constitutional rights of an inmate who was fatally shot in the head on a busy downtown Hilo street in 2006 as he tried to escape from a prison van.

The ruling by U.S. District Judge Alan C. Kay means the state will not pay damages in connection with a lawsuit filed last year by family members of slain prisoner Thane Leialoha, 28.

Leialoha was being driven back to Hawai'i Community Correctional Center in a van with nine other inmates on April 11, 2006, after a court appearance when he tried to escape.

When the van stopped at a red light, Leialoha used a key he had smuggled into the prison to unlock his hand and leg restraints, kicked or pushed open the door of the van, emerged onto Haili Street, and crawled under the van.

When Leialoha emerged on the opposite side of the van, Corrections Officer Bryan Watanabe told him "Nuff already, give it up," and began to struggle with Leialoha. Watanabe alleged that Leialoha then reached for Watanabe's gun, prompting Watanabe to spin away, according to court records.

Leialoha pushed Watanabe down and ran makai on Haili Street away from the van, and Watanabe fatally shot Leialoha in the back of the head, according to court records.

Watanabe said he was aiming at Leialoha's body or "center mass," and said he yelled to Leialoha to stop before firing.

A second corrections officer in the van also said Watanabe warned Leialoha before firing, and another witness gave conflicting statements about whether Watanabe shouted a warning before shooting, according to the ruling.

The lawsuit filed by Leialoha's family members alleged that Watanabe gave no warning before firing the fatal shot, citing statements by the nine inmates in the van and three other witnesses who said they heard no warning.

However, Kay concluded in a 55-page ruling in the case that Watanabe did yell to Leialoha to stop before firing. He noted the inmates in the van were making so much noise they could barely hear what was happening outside, and noted the three civilian witnesses were inside a nearby business or inside a truck with the windows rolled up.

Leialoha had been sentenced to 10 years in prison in 2001 for second-degree robbery and assault, and also sentenced to a consecutive five-year prison term for theft. He was released on parole, but had been rearrested on a parole violation and other minor charges shortly before the escape attempt.

The lawsuit alleged that Watanabe should have either pursued Leialoha or let him go rather than shooting him, and alleged Watanabe used excessive force, violating Leialoha's Eighth Amendment rights prohibiting "cruel and unusual punishment."

Kay disagreed, citing case law that once a person has been convicted, only "unnecessary and wanton infliction of pain" amounts to cruel and unusual punishment forbidden by the Eighth Amendment.

State Department of Public Safety policy allows corrections officers to use deadly force to stop an escaping inmate if all other means of stopping the inmate have been exhausted, and Kay ruled Watanabe did not have the option of chasing Leialoha down.

To run after the fleeing inmate would have left nine other inmates in the van in the custody of Watanabe's unarmed fellow corrections officer, putting the other officer at risk and raising the possibility of more escapes, Kay wrote.

Kay also concluded Watanabe aimed for Leialoha's body in keeping with prison policy, and did not deliberately shoot him in the head. Leialoha posed a danger as an escaping convicted felon, all other means of controlling him had been exhausted, and Watanabe had "no option" but to fire at Leialoha's center mass, Kay ruled.

The judge also found "there was a strong need for the application of force in this case."

Kay dismissed claims that the state and Watanabe were at fault because the prison van had a defective door hasp, concluding it was Leialoha's actions that put him in danger, not the faulty van door.

Eric Seitz, the lawyer representing the Leialoha family, said that after meeting with the family, "we made a decision not to appeal."

"It was a very thoroughly reasoned opinion, and I recommended in light of that that they not appeal," Seitz said. "Though I disagree with some aspects of it, I don't think that the outcome would be different if we were to appeal."