The teenager who shot at three students, killing one, at a high school in Taber, Alta. has been sentenced to three years behind bars.

The boy, now 16, pleaded guilty to one count of first-degree murder, and two counts of attempted murder.

He can't be identified because he was prosecuted under the Young Offenders Act.

"This has been a difficult, tragic set of circumstances for us, but my view is that he can be rehabilitated," said Alberta Youth Court Judge Gerald DeBow on Friday.

He will serve his time at a youth detention centre, and then spend seven years under community supervision.

The boy displayed no emotion when his lawyer entered the guilty plea.

DeBow was told that the student, who was 14 at the time of the shooting, had been bullied by peers.

He was frequently teased and beaten, starting in elementary school. In Grade 1, kids had threatened to set him on fire after dousing him with lighter fluid, according to court documents.

When he was older, they started assaulting him and then taking pictures of his injuries. By the time he was a teenager, he had become reclusive and extremely fearful.

Then in April 1999, the boy snapped. He grabbed a rifle, hundreds of rounds of ammunition, and decided to fire at the first kids he saw in the hallway of W.R. Myers High School, according to the prosecutor.

Seventeen-year-old Jason Lang died in the attack. A second teen was seriously wounded, while a third boy was shot at but not injured.

The shooter's family, who supported him in court Friday during the sentencing, said he had been prompted to commit murder after watching TV reports of a massacre at Columbine high school in Colorado eight days earlier.

Prosecutors had requested a transfer to adult court because of the severity of the crime. They also argued adult prisons offer more educational and vocational programs than youth centres.

But a judge turned down that request in October.

In youth court, the boy faced a maximum sentence of six years in jail, as well as four years of supervision after being released.

In adult court, the maximum would have been life in prison with a chance of parole after five years.

The teen had a stroke after heart surgery last year and has suffered brain damage.

His lawyer said the boy was terrified of being sent to an adult prison.

At a memorial service for his dead son in April, Rev. Dale Lang stunned many people by showing remarkable empathy for the young killer.

Lang called for healing and understanding. He said he didn't want his son's death to be in vain, and encouraged children to learn respect for each other.