DOVER, Tenn. (AP) _ A teenager who shot his school bus driver to death after she reported him for using smokeless tobacco on the bus was sentenced to life in prison.

Jason Clinard, 16, was convicted Friday on a first-degree murder charge in the death of Joyce Gregory. Clinard, who was 14 at the time of the March 2005 shooting, was tried as an adult.

Attorney Worth Lovett said his client deeply regrets the shooting.

``He told me he prays often that he can go back and do that day over again,'' Lovett said. ``There was no doubt in his mind that he had done the wrong thing and he was going to pay for it.''

Clinard looked stoical and almost relaxed as the jury returned its verdict, angering the victim's mother.

``I never saw the look I was looking for,'' Joyce Gail Wyatt said outside the courthouse. ``It bothers me that he showed no remorse.''

Gregory, 47, had reported Clinard for using smokeless tobacco on the bus, and, according to testimony, he hated her for it. He also had also been in trouble for fighting on the bus and was suspended from school in February 2005 because of the two incidents. He shot her six times, prosecutors said.

Lovett acknowledged that Clinard shot Gregory, but he asked the jury to consider a lesser charge of manslaughter. He said Clinard had been depressed and suicidal and was hearing voices.

Bud Wyatt, Gregory's father, expressed sympathy for the teen, saying he realized an example had to be made of Clinard, but he thought the verdict was ``too rough.''

Lovett said he would file a motion for a new trial. Clinard will have to serve at least 51 years in prison before being eligible for parole.

Prosecutor Dan Alsobrooks said the verdict sent a message that school violence would not be tolerated.

Clinard did not testify during the trial in this small town about 65 miles northwest of Nashville. His parents, who cried and hugged family and friends after the verdict, did not speak to reporters.