Three mental health experts who evaluated Alexandre Bissonnette on numerous occasions since he stormed a Quebec City mosque last year say the 28-year-old is not beyond help.

Psychologist Marc-André Lamontagne argued Bissonnette is an intelligent, not overly impulsive person, able to follow psychiatric treatment inside a federal prison.

"It's not delusional to say he could work on these things, given the time he'll have," the psychologist said, during his cross-examination by Crown prosecutor Thomas Jacques, on Tuesday in Quebec City.

Bissonnette's defence team is presenting its witnesses on the ninth day of sentencing arguments.

Quebec Superior Court Justice François Huot will have to determine if the man who pleaded guilty to killing six men inside the mosque on Chemin Ste-Foy on Jan. 29., 2017, will ever be eligible for parole.

'Moderate' chance of re-offending

According to Lamontagne, Bissonnette presents a"moderate" threat of re-offending, about one chance out of three, if he were let out of prison in 25 or 50 years.

The calculation is based on Bissonnette's profile when he committed his crime, his past experiences and comparisons to the backgrounds of other convicted criminals.

Sentencing hearings for Alexandre Bissonnette continue this week in Quebec City. (Jacques Boissinot/The Canadian Press)

Jacques challenged Lamontagne's assessment, arguing Bissonnette had access to professional help for his mental health problems in the years prior to the attack. While he consulted for anxiety problems and suicidal tendencies, he never disclosed that he was consumed by homicidal thoughts, Jacques said.

"He could hide his intentions," Jacques said. "He lied to several people in the past."

Lamontagne said if this were the case, experts with the Parole Board of Canada will be able to detect his bluff.

"He won't get out, it's as simple as that," he said.

Impact of bullying

On Monday, Lamontagne testified that Bissonnette had grown up in a loving and supportive family, but had been bullied by classmates throughout his school years.

The constant taunting and intimidation left its mark on his self-esteem and sense of worth, Lamontagne said, escalating into a desire of vengeance.

"He absolutely wanted to prove he is special," Lamontagne said.

Jacques remarked that this kind of bullying would be far worse in a correctional facility, limiting Bissonnette's ability to overcome his insecurities.

"It's reasonable to think it can be worse than someone poking at your notebook," he said.

Lamontagne agreed this could be the case but argued federal prisons often tried to limit these types of confrontations.

"Intimidation will be part of his journey he will have to face," Lamontagne conceded.

'Bissonnette can evolve'

​His colleague, Sylvain Faucher, a forensic psychiatrist, also said he believes Bissonnette could rehabilitated.

Contrary to "flamboyant narcissists." who are beyond reproach and refuse to admit they are wrong, Bissonnette was a "fragile narcissist," eaten away by self-doubt and anxiety, Faucher told the court.

"If we put these people in a safe environment, we have more chances [of rehabilitation] with these types of narcissists," he said.

Both experts also said Bissonnette's violent act was not necessarily fueled by an ideology. He chose a target after deciding he wanted to be recognized as a mass killer, then planning to commit suicide, they said.

"This is not an ideology he had since childhood," Faucher said. "These are all elements that lead us to believe Bissonnette can evolve."

A third forensic psychiatrist, Marie-Frédérique Allard, testified last on Tuesday, supporting her colleagues' expert opinions.

Allard met with Bissonnette on two separate occasions, also speaking with his parents. Based on her knowledge of the case, she said, he is not "a lost cause."

"I think he is capable of change, but this will depend on several elements," Allard said, namely finding people he can trust during his incarceration.

The Crown will cross-examine Allard's testimony on Wednesday morning, and could call on its own psychiatrist to assess Bissonnette's mental state, before the sentencing hearing closes by the end of this week.

The defence team told Huot they could have one last witness to call on Wednesday.

Bissonnette could receive consecutive sentences, which would mean up to 150 years in prison.

His legal team is hoping he receives concurrent sentences, which would make him eligible to apply for parole after 25 years.