UK Police have released video of a man roaming gardens in London armed with a machete after beheading an elderly woman at her home.  

The case happened on September 4 last year when 25 year old Nicholas Salvador, went on a rampage in the north London suburb of Edmonton.

By the time a police helicopter had tracked him down, he'd already broken into a house and beheaded a woman in her eighties.

A camera on board the helicopter recorded the scene as police closed in on the armed and extremely dangerous assailant. 

Police eventually managed to restrain Salvador.

In court this week, psychiatrists described him as a paranoid schizophrenic, who thought the woman he'd murdered was either the ghost of Adolf Hitler or a demon in the form of an old lady.

The court cleared him of murder on the grounds of insanity but Salvador will be detained indefinitely in a psychiatric hospital.