An autopsy report says Amber Hilberling had methamphetamine in her system when she hanged herself in prison in October.

She was serving 25 years for pushing her husband out of the window of a high-rise apartment in Tulsa five years ago.

Her parents have gone on national television to say they think she was murdered but the Medical Examiner says she committed suicide.

Hilberling had twice tested positive for illegal drugs while in prison.