A psychologist from Alberta Hospital who examined Matthew de Grood following the murders of five young people at a northwest house party two years ago took the stand on Thursday to testify for the defence.

De Grood, 24, is accused of killing Joshua Hunter, Lawrence Hong, Zackariah Rathwell, Kaiti Perras and Jordan Segura in April of 2014.

He pleaded not guilty to the murders on the first day of the trial and in an agreed statement of facts, admitted to killing all five victims.

On Wednesday, two psychiatrists who evaluated de Grood following his arrest took the stand and both said he showed signs and symptoms of psychosis when he was examined.

On Thursday, the court heard from an expert Edmonton psychologist who also examined de Grood at Alberta Hospital.

Dr. Andrew Haag told the court that he saw de Grood in the fall of 2014 and that his opinion is independent of the other doctors who have already testified in the case.

He said that de Grood suffered from "a disease of the mind at the time" of the killings and that he diagnosed the disorder as schizophrenia.

Dr. Haag said that diagnosis intefered with de Grood's ability to tell the difference between right and wrong. He added that despite the inability to understand moral issues, de Grood did have a full understanding of what went on during the stabbings, drawing out a diagram that reflected the physical evidence collected at the scene.

During his testimony, Dr. Haag, says he tried several different methods to see if de Grood was faking a mental illness and said he "had a legitimate psychotic disorder."

Dr. Haag told the court that de Grood told him that he believed the apocalypse was about to occur, along with a major war to coincide with a blood moon that evening.

He testified that de Grood told him of hallucinations of a "sun god" and voices instructing him to "kill them all before they kill you". Dr. Haag said that de Grood said he believed he was in danger, that he would be killed and there would be "an outbreak of vampires".

During cross examination, Dr. Haag told the court that he has completed about 100 assessments regarding criminal responsibility.

“His findings in his report were consistent with the findings of the two forensic psychiatrists who’ve already testified. His findings were, at the time of the events, my client suffered from a disease of the mind, he was psychotic, probably schizophrenic, and that as a result of this mental illness he was suffering he was incapable of understanding what he was doing. He believed he was acting in self-defence. He believed at the time they occurred that he was about to be killed himself and his only alternative was to defend himself,” said defence attorney Allen Fay.

“The important thing is that the truth come before the court. We have three experts giving three expert opinions. I note they were independent opinions and the opinions are the same but the important thing is for the truth to come out,” said Crown prosecutor, Neil Wiberg.

The last witness for the defence took the stand on Thursday and Fay says he is pleased with the way the evidence was presented.

"The experts who testified certainly support my position that my client was not criminally responsible at the time these events occurred," he said.

According to provincial court records, between April 2013 and March 2015, 38 people were found not criminally responsible for the crimes they were accused of.

If Justice Eric Macklin finds de Grood not criminally responsible he will be sent to a secure psychiatric facility.

“He will be sent to a secure psychiatric facility such as Alberta Hospital Edmonton or the Southern Alberta Forensic Psychiatric Centre. He will be detained there subject to review by the Alberta Review Board and he will remain there until such time as the Alberta Review Board feels that any risk that might exist will be successfully managed in the community,” said Fay.

“Everyone is a loser in this particular case. Five outstanding people were killed and nothing, no decision, will get around that,” said Wiberg.

Court was adjourned just after noon on Thursday and will resume on Tuesday for the submission of final arguments.

For the latest on the de Grood trial, follow Ina Sidhu and Jordan Kanygin on twitter