A Sydney man who filmed, raped, tortured, kidnapped and murdered his terrified niece before dumping her body in a blowhole says 'I let my own problems spill into the family home'.
'This moment in my life has kept me awake at night in tears and I still have nightmares,' Derek Barrett wrote in a letter of apology to his victim's heartbroken mother.
Already in jail for at least 34 years and six months for the murder and kidnapping, the former IT worker faced a resumed sentence hearing in the NSW Supreme Court on Tuesday in relation to the filmed sex attacks.