Kevin Fletcher, 32, was found dead in his home by his girlfriend last Friday morning.
Police who have renewed their appeal for information, say the murdered man was vulnerable and defenceless.
Detective Chief Inspector Richard Harkness said: 'This was a frenzied attack on a man who lived alone and was unable to defend himself against someone intent on causing utterly horrific injuries.'
Mr Harkness said the attack was unprovoked and police have not yet established a motive for the murder but are studying a number of lines of inquiry.
Police know Mr Fletcher's father took him home to his flat and was with him until 10.30pm last Thursday.
They are urgently trying to establish his movements after that and want anyone saw him to contact them.
