Vincent Tabak admitted to killing Joanna Yeates after she rejected his kiss, a court heard.
Tabak, 33, claims he panicked after Yeates screamed when he tried to kiss her. He strangled her around the throat and covered her mouth with his hand until her body went limp.
Yeates, a 25-year-old landscape architect, and Tabak, a Dutch engineer, were flatmates in the Clifton area of Bristol.
Both were home alone when Yeates saw Tabak through the window and waved him over to her flat. She had just returned from drinks with friends.
William Clegg of the defence said: “Vincent Tabak never intended to kill her, nothing had been planned, nothing was premeditated. It was pure chance.”
Tabak has pled guilty to manslaughter but denies charges of murder.
Clegg, QC, told the court both victim and killer were victims of chance and bad timing.
“There was a nod and an acknowledgement between the two and she indicated or beckoned for him to retrace his steps and come in,” Clegg said.
“She opened her front door and invited him in. What happened next? He took off his coat and hung it on the coat rack in her hall.
“She offered him a drink. He declined as he was driving later. They introduced themselves to each other and chatted as neighbours would.
“She said her boyfriend was away and she was alone and he said his girlfriend was away and he was alone. As the two of them talked inside the flat, Tabak completely misread the situation that he had walked into.
“Joanna was only being sociable, as many neighbours would be, particularly as it was Christmas.
“He mis-read her friendliness towards him and made a move towards her as if he was about to kiss her on the lips.
“He put one hand behind her back, in the middle of her back, to pull her closer to him.
“She screamed, it was a loud piercing scream. He panicked. He put her hand over her mouth to stifle the screams. He said to her, ‘Stop screaming’.
He apologised and said he was sorry. He took his hand away and she carried on screaming. He panicked. He put one hand around her throat and the other over her mouth.
“In seconds, far less than a minute, Joanna went limp. She was dead.”
Clegg went on to say that Tabak’s actions after Yeates’ death were “frankly disgusting.”
He said Tabak acted cold and calculating, with evidence that Tabak researched unsolved murder cases online and found satellite imagery of the site at which he buried Yeates’ body in the snow.
But Clegg reminded the court Tabak was not on trial for hiding the body in seclusion in North Somerset. The jury must only decide if Tabak intended to kill Yeates.
The case, at Bristol Crown Court, will resume on Thursday when Tabak will give evidence.