This is the terrifying moment a blood-soaked killer was detained by police after "almost decapitating" his victim in a brutal knife attack.
Dramatic body-cam footage shows PC Richard Edge with his taser directed on crazed Martin McDermott moments after he murdered 44-year-old Leslie Salmon.
The officer can be heard barking orders at McDermott, whose hands are covered in blood, as he approaches him in the garden of a bail hostel in Derby in August last year.
With his taser draw, PC Edge yells: "Stand still, if you make any threats I will taser you.
"Turn around, walk forward, put your hands on that shed, stand still.
"If you make any threats to myself or others I will taser you, do you understand?"