shane dunn , 25 , from tunbridge wells , stabbed victim ian garrod , 55 , in the neck after going back to ian garrod 's home in medway for sex in september last year .
but when the 55-year-old sat on the bed , dunn - who was said to be ` cool as a cucumber ' during the attack - stabbed him in the throat .
the callous attacker even pretended to call an ambulance for his victim , but instead left him for dead with a 6cm-deep wound .