Dean Amies was killed in the collision.
Police allege Michael Cruickshank sent the Prime Minister threatening emails.
He could face two years in prison.
Clayton Patrick Nathan-Graves was found dead on a boat on October 5, 2019.
The body of Tania Hadley was found on Friday morning.
Jamie Foster groped and raped the woman in a motel.
He only served 405 days of his six-year sentence.
The full bench of judges were unanimous in their decision.
A man who stabbed one of the country's most notorious murderers more than 40 times has been sentenced to preventive detention.