The jury at the Richard Kachkar murder trial is expected to hear Thursday from the first of three psychiatrists that, according to the defence, will back up the arguments of Kachkar's legal team that the 46 year-old should be found not criminally responsible for the death of Toronto Police Sgt. Ryan Russell.

Kachkar's lawyer Bob Richardson has told court that the three professionals all independently came to the same conclusion, that he was suffering from a mental disorder and should be found not criminally responsible in the officer's death.

Dr. Philip Klassen, Vice-President of Medical Affairs at Ontario Shores Centre for Mental Health Sciences is expected to be called to take the witnesses stand on Thursday and his testimony could last into Friday.

Richardson's defence is under Section 16 of the Criminal Code which states "no person is criminally responsible for an act committed or an omission made while suffering from a mental disorder that rendered the person incapable of appreciating the nature and quality of the act or omission or of knowing that it was wrong."

By law a person is considered to be criminally responsible unless proven otherwise. It's up to Kachkar's lawyer to prove he was suffering from a mental illness.