SAINT JOHN, N.B. -- Donnie Snook, a former municipal politician and youth worker in New Brunswick, said Friday he can't explain why, as a victim of child sex abuse himself, he sexually assaulted and made pornographic images of boys over a 12-year span.

Snook addressed provincial court in Saint John at his sentencing hearing, apologizing for the years of "sadness and darkness" he created in the lives of 17 young kids.

"I stand before you ashamed of my actions," said Snook, 41.

"If anyone should have known better, it was me."

Snook told the court he was sexually abused as a 10-year-old in Newfoundland and it is difficult for him to understand how he could inflict that kind of pain onto others.

"I became the very thing I hated most: a person who molested children," he said.

"I will never hurt a child or young person this way again."

Snook pleaded guilty in May to 46 charges including sexual assault and possessing, distributing and making child pornography. The crimes, which began in January 2001 and went on until his arrest in January of this year, involved 17 boys, most of whom were from the Saint John area and between the ages of five and 15 at the time of the offences.

Crown lawyer Karen Lee Lamrock argued that Snook should be sentenced to 21 years in prison because while he was seen as a role model for his work with youth programs and as a city councillor in Saint John, he broke the public's trust by preying on young boys.

"It was all those things that gave him access to children," Lamrock said.

She read two victim impact statements, one from a boy who says he will bear the emotional scars of what happened to him for the rest of his life.

"What happened to me will stay with me forever. I feel it hard to live a normal life because of what happened to me at a young age," Lamrock read.

"Having that happen to you can only cripple you emotionally."

In another victim impact statement, Lamrock read from a mother of a boy who says she believes she failed her son in not doing more to prevent the abuse.

"Ever since Jan. 9, 2013, I feel like the worst mother in the world. I didn't do enough to protect him," Lamrock quoted the mother as saying.

"I feel betrayed by Mr Snook. My son feels betrayed by the person he most looked up to in the world."

Lamrock told provincial court Thursday that Snook created a "permissive atmosphere" in his home by luring boys with cash, allowing them to consume alcohol and marijuana, and having them carry out sex acts -- something she urged Judge Alfred Brien to consider in sentencing.

"Inducement by money is an extremely important aggravating factor," she said.

Snook was arrested by the RCMP after an investigation that began in 2011 involving the Saint John and Toronto police. After his arrest, police seized his computers and discovered more than 15,000 photos and videos of child pornography, Lamrock has told the court.

Lamrock said Snook was arrested after he offered to put "one of his boys" on video while chatting online with an undercover officer. There was a boy in Snook's home at the time of his arrest, Lamrock said.

During the two-day sentencing hearing, court heard that in some cases, Snook would chat online with boys while pretending to be a teenage girl. In one chat session, a 13-year-old boy began to take his clothes off at Snook's request but stopped, at which point Snook told the boy he would post on Facebook videos of him undressing for his friends to see if he didn't continue, according to a transcript of the chat session entered as evidence.

"I knew I was doing wrong," Snook said Friday. "I was like an addict looking for my next online high."

Lamrock cited a report by a psychologist who interviewed Snook following his arrest. The review by Mary Ann Campbell concluded Snook had no emotional relationship with the children he abused.

"It was strictly for sexual pleasure," Lamrock said.

Campbell concluded in her report that Snook's behaviour was driven by a "deviant sexual interest in children" though she is optimistic about his chances for rehabilitation, Lamrock said.

Testifying for the Crown, Campbell said Snook "regrets his actions after the fact, but the regret is not enough to stop reoffending."

The defence argued for a 12-year prison term, saying Snook is willing to help the victims in any way he can and is eager to undergo rehabilitation.

"He looks forward to treatment to deal with the urges he has," said defence lawyer Peter White, adding that Snook co-operated with investigators after he was arrested.

Lamrock agreed, saying investigators would not have known of some of Snook's victims if he didn't co-operate with them.

Brien will deliver his sentencing decision on Oct. 10.

Defence lawyer Dennis Boyle said Snook's accusation that he was abused as a child has been referred to the Royal Newfoundland Constabulary.

Snook was elected to city council in 2008 and was involved in community organizations including the Inner City Youth Ministry, which provides sports programs, mentoring and lunches at three schools.

Outside court, Judith Meinert-Thomas, a former board member of the Inner City Youth Ministry, said she hopes the sentence Snook receives includes some form of court-ordered counselling.

"For Mr. Snook, I hope that he is able to rehabilitate himself and have some kind of useful life," Meinert-Thomas said.

"I'd like to think that the children will be supervised and have treatment and therapy. They are at the core of everybody's hope for this case."

In a separate matter, Snook also faces two counts each of sexual assault and sexual interference involving a boy for incidents alleged to have occurred in the mid-1990s in western Newfoundland. That case has been adjourned until Oct. 29.