WATCH: Psychiatrist testifies Kelowna killer was insane

Conor Grossmith, 26, knew he had a hammer in his hand and he knew he was striking another person with it but that — according to his lawyer — is where Grossmith stops understanding the consequences of his actions.

“The accused was unable to know that his actions were wrong at the time of the offence,” says defence lawyer, Joe Gordon.

The offence happened in September 2012 in Kelowna’s Mission where, after drinking at least two litres of wine, Grossmith attacked his mother with a hammer. Kate Gilchrist, 57, died nine days later of severe head injuries.

A forensic psychiatrist for the defence testified Tuesday that Grossmith was temporarily insane.

“In other words he’s basically saying that the accused is not criminally responsible because he wasn’t capable of understanding that what he did was wrong,” says Gordon.

An issue at trial is what role if any did Grossmith’s drunkenness play in his crime.

The defence contends alcohol had nothing to do with it — that Grossmith never displayed signs of violence while under the influence.

Grosssmith was about four times over the legal driving limit. However, self-induced intoxication is not a defence to the killing.

“It doesn’t reduce second-degree murder to manslaughter and consequently it’s important to know whether alcohol caused this — self induced intoxication caused this or was it an underlying psychosis and this doctor has indicated that it’s a well documented history of psychosis with or without alcohol on board,” says Gordon.

The defence is arguing the killer is not criminally responsible due to a mental disorder.

If the judge agrees, Grossmith will be sent to a secure psychiatric institute until it’s deemed safe to release him.

Grossmith’s father is attending the hearing. Harry grossmith is a former CEO with the united way.