Lindsay, the son of a former Edmonton police chief, was facing charges in two separate attacks in BC - one on an undercover RCMP officer conducting a sting operation, and one where he stabbed another inmate in the eye with a pencil while in custody.
Lindsay has admitted to both assaults, but told the court that he was acting in self-defence. He believed he was being hunted by a group of serial killers.
During the trial, a psychiatrist testified that Lindsay is suffering from schizophrenia and could not fully appreciate his actions.
The prosecution argued that he should be held accountable for the assaults.
In finding Lindsay not criminally responsible due to mental disorder, Judge Dev Dley said he still believes Lindsay is an exceptionally dangerous person.
The ruling does not affect the second-degree murder charges that the Linsday faces in Alberta in the death of his former girlfriend,Turner. A trial date for that case has not been set.
During the B.C. assault trial, Linsday said he killed Turner and dumped her body near Innisfail, Alta, because he thought she was a witch. Her remains were found in 2011.