A 29-year old killed a Magherafelt man in his flat then sat drinking in the victim's home for several days whilst his remains lay in a bedroom.
Details surrounding the death of retired police officer Brian Coulter (62) emerged during a plea hearing at Belfast Crown Court.
Adrian Sebastian Nowak has admitted a charge of manslaughter.
Mr Coulter was last seen alive on October 13 2021 in the company of Nowak and his body was discovered in his flat in the Sandy Braes area of Magherafelt days later by his sister.
He was killed by Nowak some time between October 13 and 14, and evidence in the flat suggested the deceased was then placed in the shower and washed by Nowak before his remains were moved to a bedroom.
Crown barrister Richard Weir KC told Mr Justice O'Hara that Mr Coulter was an alcoholic and a vulnerable man with multiple health issues.
Mr Weir revealed that around noon on October 18 2021, Mr Coulter's sister called at his flat and let herself in via an unlocked door.
The flat was "in a state of disarray" and a man was asleep on the sofa. She went to the front bedroom and observed her brother lying on the floor.
At this point the man on the sofa - Nowak - woke up, adopted a threatening stance and roared at her. This caused her to flee and once outside, she called police.
As she was waiting for police, Nowak left the flat. When police arrived, they noticed blood in the living room, hallway and bathroom.
Mr Coulter's remains were removed from the bedroom and a post mortem concluded death was due to blunt force injuries to his head, neck and chest.
He also suffered a bleed to the brain and had bruises on his chest and back as well as bruising to his wrists which were consistent with defensive injuries.
When Nowak, with an address at Colvil Street in Belfast, was arrested, he spat at and tried to headbutt officers. While at Musgrave Custody Suite, he gave a false name.
He was interviewed 15 times and whilst he gave a 'no comment' response throughout, he gave a pre-prepared statement during the final interview.
In it, Nowak said he knew Mr Coulter who invited him to his flat where they drank together. He also claimed that after an argument, Mr Coulter hit him - and he struck him back twice in self-defence.
Nowak added that after this, he moved Mr Coulter's body to the bedroom then stayed in the flat drinking for a few days before a lady arrived at the property.
Defence barrister Michael Duffy SC said his client was also an alcoholic, and whilst he branded the fatal incident as "unsavoury" and "unjustifiable", he said it was not a case of "persistent wanton violence" but rather one in which one or two blows were administered.
Mr Justice O'Hara said there was an element of "victim-blaming" regarding Nowak's version of events.
Saying he needed some time to reflect on what he had heard, the senior judge said he would sentence Nowak on Friday.