The 19-year-old man convicted of killing teenager Stefanie Rengel broke his silence about the case Thursday, telling a Toronto court he can't forgive himself for his actions. Stephanie Rengel was stabbed to death on New Year's Day 2008. (Toronto Police Service)

The teen, who can only be identified as D.B. because he was 17 when he committed the crime, pleaded guilty earlier this year to killing the 14-year-old outside her east Toronto home and leaving her to die in a snowbank on New Year's Day 2008.

D.B.'s first public comments came on the second day of his sentencing hearing at Ontario Superior Court.

"To Stefanie's family, I am so sorry," he said.

Then, addressing his victim, D.B. said: "Stefanie, I am sorry. I want to ask for forgiveness but realize I can't even forgive myself. I hate myself for the decision I made that night."

He added that he deserves whatever sentence he gets.

"I will bear the very heavy burden of what I did forever. Not one day will go by when I don't regret what I did."

Rengel's mother, Patricia Hung, wiped away tears as D.B. finished speaking.

Adult sentence sought

Crown prosecutors want the teen sentenced as an adult.

He was four days shy of his 18th birthday when he committed the crime, so he was charged as a young offender.

A psychiatrist testifying at the hearing Thursday told the court D.B. could be rehabilitated in 10 years if he received a youth sentence.

Dr. Derek Pallandi said the teen has made progress in treatment since his arrest.

Pallandi also agreed with testimony Wednesday from psychiatrist and Crown witness Dr. Lisa Ramshaw that D.B. is immature, has attention deficit disorder and showed very poor judgment when it came to his relationships.

Girlfriend, Rengel never met

Ontario Superior Court has been told D.B. carried out the crime after his girlfriend, Melissa Todorovic, pressured him into killing Rengel out of jealousy.

Todorovic and Rengel had never met.

Todorovic was convicted of first-degree murder in a separate trial. She was sentenced as an adult to life with no chance of parole for seven years, the maximum for someone under 16.

Pallandi told the court D.B. has a long history of fighting at school with other boys, but in those cases, he did not use a weapon.

Whether he will reoffend is more difficult to assess, Pallandi said, because the teenager's personality is still developing.

Pallandi recommended continued therapy in a youth setting, saying he felt D.B. would become more aggressive if sent to an adult penitentiary.

D.B. is interested in pursuing his education, and since getting medication for attention deficit disorder while in custody, he has been studying and concentrating better than he has in years, Pallandi said.

The hearing will continue Friday.