04/06/2017 05:13 EDT | Updated 04/06/2017 08:17 EDT

Matthew De Grood, Calgary Mass Killer, A Model Patient: Psychiatrist

It's been almost three years since he killed five people at a house party.

CALGARY — A Calgary man who killed five people with a knife is blaming the crimes on his mental illness and is trying to reassure the victim's families that he is getting better.

Matthew de Grood was suffering from a mental disorder when he attacked and killed Zackariah Rathwell, 21; Jordan Segura, 22; Josh Hunter, 23; Kaitlin Perras, 23, and Lawrence Hong, 27 at a house party three years ago.

The judge in the case ruled de Grood didn't appreciate his actions were wrong and was not criminally responsible.

The Alberta Review Board is determining whether de Grood, who is housed in a secure hospital, should be granted more freedom.

Matthew de Grood was found not criminally responsible after stabbing five people to death at a house party. (Photo: Facebook)

In statement read by his lawyer, de Grood says he understands the pain of the families who watched his every move throughout the hearing.

"It breaks my heart that the good times that they had with their loved ones are over. They are shocked, deeply sad, fearful and angry over what I have done through my illness," he said in the statement.

"They may not care that I am a schizophrenic. The act of killing five innocent people and putting their families through that agony is unconscionable. To them, I am either a very evil person or a psychotic individual who is dangerous and can't be trusted."

In his statement de Grood said he would have sought treatment if he had known he was ill and has been responding well to treatment.

"He's always going to be known for what he's done and this is going to have an effect on his life."

"It is hard for me to imagine what I could do to ease the pain I have caused, but I promise to do everything in my power to ensure I never relapse. I respect the decisions of the board."

Fay said de Grood had planned to read his statement but was unable to do so.

"He initially wanted to but certainly, hearing from the victims was very difficult for him. He was overwhelmed to the point where he did not think he could do so."

Several family members read victim impact statements and most were angry that they had to relive the pain of the loss just a week before the third anniversary of the deaths.

"I'm appalled to be here today," said Gregg Perras. "I cannot express the anguish and anger that I feel. Our nightmare continues every day and days like a real-life horror."

Patty Segura said the justice system has made her feel invisible.

"What right does Matthew de Grood have to do this severe damage? They were all good kids," Segura said. "My future is gone."

The family members also made a statement outside of court.

"We are now three years into this journey and are unwilling participants in a process that to us, makes little sense and only adds to our nightmare," said Perras.

"We hold on to the hope that our involvement in the review board process will bring some healing and that our voices will be heard, but regrettably, that is not our experience. This review process only derails our healing."

Ronda-Lee Rathwell said she has no doubt that de Grood feels horrible for what he has done but he needs to follow up that sentiment with action.

"If he truly is sorry and never wants it to happen again, then he should voluntarily commit himself to be institutionalized or be hospitalized forever," said Rathwell.

De Grood has been a model patient but that any reintegration back into society will be a slow process, a psychiatrist told the hearing.

Dr. Sergio Santana says de Grood is on medication for schizophrenia and hasn't had any symptoms for almost three years. He said the symptoms have been in "full remission" since July, 2014.

He said de Grood is considered at a "low level" for violent recidivism, but acknowledged that is based on him continuing to take his medication and staying in a hospital setting.

Possible risk of relapse

A failure to take medication and stressors could lead to a relapse if de Grood was outside of the hospital setting, Santana said.

"The risk of recidivism is low but the potential that he could do something very violent is very high."

"He would become psychotic, deluded, start hearing voices and the danger is he might respond to those delusions and hallucinations and believe they're real."

Santana is recommending de Grood be allowed to walk around the hospital grounds for up to half an hour and to attend doctors' appointments in Calgary while under strict supervision.

"He's always going to be known for what he's done and this is going to have an effect on his life," said Santana.

There's no timeframe on when the review board will release its decision.

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