Schizophrenic who started smoking cannabis aged nine is jailed for life after killing both his sister and mother
- Peter Fox, 27, killed mother Bernadette, 57, and sister Sarah, 27
- Liverpool Crown Court heard he was a drug user with history of violence
- Sister's neighbours said they heard screams of 'help me' as he stabbed her
- Fox had previously claimed to have been a spy 'ordered to kill people'
- He was discharged by mental health service weeks before the killings due to a 'breakdown in communications' between agencies