BOSTON - A former student at an elite Canadian boarding school pleaded guilty Wednesday to taking off another student's pants and assaulting him in a hotel room during a 2007 school trip to Boston.

He apologized to the victim and his family before he was sentenced to four years' probation for assault and battery.

"I used to be somewhat of a bully, but I've been working hard to make myself a better and more caring person," he said. "I'm committed to showing you and your honour that this apology is more than just words."

The Ottawa man, now 19, also faced an indecent assault and battery charge, which will be dropped if he completes a concurrent four years of pretrial probation.

Prosecutors accused him of penetrating the victim's anus with his fingers while another student held him down during the November 2007 attack, which one student filmed.

But under questioning by Suffolk Superior Court Judge John Cratsley, he said only that he touched the victim's buttocks area in a way that "(the victim) himself felt penetration."

The victim's parents have sued him, other students involved in the assault and the school, Ashbury College in Ottawa, which says it handled the situation appropriately. In a victim impact statement, the now-18-year-old victim said the assault did lingering damage to his family.

"So before you go and make half-hearted, insincere apologies and condolences to the public, really take a long while to think about what you have done to us," he said. "Until you do that, I brush aside any attempt you make to apologize to us. You have done something horrible and sick, and you must pay for it."

The victim and his family declined to comment on the apology after the hearing.

The assault happened during a history trip to Boston by students of Ashford College, a prep school which has a boarding school for high school-aged students.

Prosecutors said the victim was lying on a bed at Midtown Hotel watching TV with three roommates on the night of Nov. 16, when the Ottawa man and three other male students rushed into the room. Prosecutors said a boy held the victim down, while the Ottawa man, then 17, took off the victim's pants and assaulted him, while saying, "Take it."

The boy accused of holding down the victim is being tried separately in juvenile court.

The Ottawa man was later expelled from the school. The victim's mother said he and his siblings left Ashbury College.

"This incident was purposely designed by the accused to be an ultimate act of public humiliation of a 16-year-old boy," the victim's mother said in a statement read by the prosecutor. "This has been a cloud over my son, and I know that he will carry this scar with him for the rest of his life."

David Apfel, the lawyer for the Ottawa man, said his client became "a pariah in his community" after the incident and was forced to attend boarding school overseas in Switzerland. But he said he became an exemplary student, involved in athletics, student government and the student newspaper, and was genuinely remorseful for what he'd done.

Apfel asked for two years' probation, saying four years' probation was too long for a "one minute act of adolescent stupidity."

Cratsley commended the man for acknowledging his crime, but imposed the prosecutor's request of four years' probation.

"There are consequences when you take such evil acts and harm other people," Cratsley said.