SURREY, B.C. -- A young man's belief that he could cure his paralyzing anxiety around women by having sex drove him to fatally attack a 15-year-old girl in a Delta, B.C. park, a forensic psychologist says.

Robert Ley told a sentencing hearing that he believes the offender is a motivated and intelligent person who would be receptive to treatment and should be detained in a provincial institution rather than in a federal prison, where rehabilitation programs would be less effective.

The man can't be named because he was 17 when he attacked Laura Szendrei in September 2010, hitting her repeatedly over the head with a pipe in an attempt to subdue and rape her while she was walking to meet friends in broad daylight.

"There's no doubt whatsoever federal prisons are a dangerous, violent, risky place," Ley said Thursday. "Almost certainly in a federal prison system, (he) would need to adopt very tough, aggressive, and perhaps a violent stance towards other inmates in order to protect himself."

Ley said the man, who is now 21 and pleaded guilty to second-degree murder last year, would get faster access to treatment programs at a provincial institution for sex offenders in Chilliwack, B.C.

He also argued the bullying and aggression that typically occurs in prisons would not be conducive to teaching the offender how to live effectively in the community after he's been released.

The man was so painfully self-conscious when he attacked Szendrei that he was incapable of interacting with young women, Ley said.

"He had never kissed a girl in his adolescence, he had never held a girl's hand, he had never dated," Ley said. "He could not talk to an adolescent girl even when they spoke to him first. He was absolutely paralyzed by his anxiety and fear around women."

Court has already heard from forensic psychiatrists who said the man posed a high risk to reoffend and that he showed no remorse for the murder, for which he will be sentenced either as an adult or a youth.

If sentenced as an adult, the man would receive life in prison with eligibility for parole after seven years. If he receives a youth sentence, he will get seven years, with four years behind bars and the remaining served in the community.

Ley interviewed the offender for nearly 10 hours earlier this year, and his report painted a picture of someone who hit puberty later than most boys and was picked on in high school because of his small size.

He had few friends, was depressed and spent hours playing video games on his family's computer.

But it was his lack of experience around girls and his belief that other boys his age were having sex that seemed to preoccupy his thoughts in the months leading up to Szendrei's murder, the psychologist said.

"(He) did not have a large social circle, he identified three, four close friends, mostly video-gaming buddies," Ley said. "Some of them got girlfriends, and then they started talking to (him) about his sexual experiences, so he now felt further behind the pace."

Five months before Szendrei's death, the man embarked on what Ley said was a "grossly misguided attempt" to get over the tension he felt about his lack of sexual encounters.

Ley said the man confessed to police during an undercover sting, and after his subsequent arrest, that he attacked three women between April and July 2010. In one instance, he ran behind a woman and tried to grab her buttocks. In another, he tried to pull down a woman's pants while she was jogging, hoping to grab or fondle her.

In the third attack, court heard he hit a woman with a stick, "with an idea of disabling her that he could then feel what a woman felt like," presumably wanting to touch her or have a direct sexual experience, Ley said.

The sexually motivated attacks escalated over the course of several months, ending with Szendrei's death.

During cross-examination, Crown lawyer Wendy Stephen suggested that Ley too readily accepted what the man said was his motivation for attacking Szendrei.

Noting that the man was arrested five months after Szendrei's murder, Stephen asked: "That's obviously plenty of time to think about a situation and come up with a rationale, reason, motivation, right?"

Ley insisted the man's explanation was credible, saying he believed the tragic death could have been prevented if the man could have received treatment or been educated.

"If one was treating (him) in the months or years before this offence occurred it would have been relatively easy to deter him from this particular path," he said. "Some basic information around normative, male sexual experiences and activities would likely have been helpful."

Ley said the man is preparing himself for years behind bars, whether he is incarcerated in a federal or provincial institution.

"He's been very dedicated to personal training and weight lifting," Ley said. "He wanted to build up his size and strength in the event that he went into the federal prison system, such that he could better defend himself."