The parents of the Quebec City mosque shooter are calling the sentence handed down to their son “very severe.”

In an open letter to the media, Manon Marchand and Raymond Bissonnette write: “Unlike other countries, Canada has chosen an open door policy, welcoming people from all over the world and giving them hope for a second chance in life. Why deny convicts even the faintest hope?”

Their son, Alexandre Bissonnette was ordered to serve six life sentences with no chance of parole for 40 years after fatally shooting six men at a mosque in Quebec City on Jan. 29, 2017.

In the ruling, Justice Francois Huot said Bissonnette should serve six sentences of 25 years concurrently for the murder charges and another 15 years, also to be served concurrently, for attempted murder.

Huot rejected the Crown's call to sentence Bissonnette to 150 years with no chance of parole, arguing a sentence of 50 years or more would constitute cruel and unusual punishment under the Canadian Charter of Rights and Freedoms.

Sentences that exceed an offender's life expectancy and offer no reasonable hope of release are "grossly disproportionate and totally incompatible with human dignity," he wrote in his 246-page decision.

After the verdict was heard on Friday, members of the Muslim community said they were “disappointed” and “astonished” by the outcome.

"(Bissonnette) declared he wanted to kill more people, he was disappointed in himself he didn’t kill enough,” said imam Hassan Guillet, adding that the victims' families were looking for a peace of mind and healing that the verdict did not deliver.

“We know, after 40 years, Mr. Bissonnette will be 67, we don’t know if he’ll be alive or not, but the orphans, very likely will be still alive and the debate will be reopened again,” he said.

In the letter, Bissonnette’s parents said their son was the victim of bullying while growing up.

“Alexandre suffered psychological and physical bullying during his school years which had devastating effects on his personality. If we really want to prevent such a tragedy from happening again, it seems to me that the solution is not to lock someone up forever, but rather try to better understand and prevent bullying, which is a serious societal problem that continues to make victims amongst our young,” the letter read.

Read the letter in full here:

- With files from The Canadian Press