The man accused of murdering landscape architect Jo Yeates drove to Asda with her body in his car, a court heard.
Bristol Crown Court was told by prosecutors that Vincent Tabak, who has admitted Miss Yeates's manslaughter, bought rock salt, crisps and beer.
Nigel Lickley QC, said Miss Yeates's body "must" have been in the car boot when he visited the Bedminster store.
The body of Miss Yeates was found on a verge near Bristol on Christmas Day. Tabak denies her murder.
The jury was told the 33-year-old Dutch engineer went to the Asda store twice and did his shopping on the second visit.
Mr Lickley told the court that Tabak texted his girlfriend after the killing, saying he was "bored".Neighbouring flat
The court was told that Tabak had searched for information on the length of murder and manslaughter sentences.
He also searched online for "body decomposition time" while detectives were hunting for Miss Yeates.
When police revealed a pizza and its box were missing from Miss Yeates's flat, he searched the internet for the dates of refuse collections in the Clifton area, Mr Lickley said.
"When alone at work or at home his internet activity became ever more consumed, following news items as if almost following the police investigation as it unfolded," he said.
Tabak also constantly searched the Avon and Somerset Police website for details of the case and used Google Maps to view the location Miss Yeates's body was found, he added.
Miss Yeates, from Ampfield, Hampshire, disappeared on 17 December 2010 after going for drinks with colleagues in Bristol city centre.
Jurors were shown CCTV of her visiting Bargain Booze on the way home to her flat in Canynge Road.
Despite living in a neighbouring flat, Miss Yeates did not know Tabak, the court heard.
On the night of her death, Miss Yeates had "settled down for the evening when she was interrupted by Vincent Tabak", Mr Lickley said.'Screams heard'
"Vincent Tabak strangled her with his hand or hands. He held her throat hard enough and for long enough to kill her.
He said a first scream was followed by a second "lower, muffled sound" and then a thud.
He told the court: "Having killed her, he drove her body in the boot of a Renault Megane and deposited her body where it was found."
Forensic evidence showed blood on the wall beside Longwood Lane, consistent with Tabak trying and failing to put Miss Yeates's body over the wall, Mr Lickley said.
He said leaves had been placed deliberately over Miss Yeates's body and snow had then fallen on her.
The jury was told how Miss Yeates's body was found by a couple on Christmas morning in Failand.
Miss Yeates's parents, David and Teresa, left the courtroom while the jury was shown images of her snow-covered body.
The prosecutor said that during the following weeks, Tabak was "in complete control" and "knew what he was doing".
Miss Yeates's boyfriend Greg Reardon described Tabak and his girlfriend, Tanja Morson, as "quiet, keeping themselves to themselves," Mr Lickley said, and had only met them once.
When he returned home from visiting family in Sheffield, he thought Miss Yeates was out and rang her phone which had been left inside their flat.Birthday party
After calling friends and family in a bid to find her, Mr Reardon called police. His 999 call was played to the jury.
"It is a striking feature of this case that, as one young man became more and more worried about his missing girlfriend, there, on the other side of the common wall, was her killer," said Mr Lickley.
Later that night, police knocked on the door of Tabak's flat. The officer who spoke to him said Tabak looked as if he had just woken up.
When asked if he had seen anything Tabak said "no" and appeared calm, but when Miss Morsen came to the door she was "visibly shocked and concerned".
In the following days, the prosecution said, Tabak emailed his girlfriend to say he hoped Miss Yeates was "discovered healthy and well".
Tabak and his girlfriend spent the New Year in Holland, where Miss Morson contacted police with information about their landlord Christopher Jefferies - who was arrested and later cleared.
But when detectives flew to the Netherlands to take a statement from the couple, Tabak appeared to offer an inconsistent version of events, the jury was told.
Mr Lickley said: "They asked Tabak to provide a DNA mouth-swab and fingerprint... He would have to be eliminated from inquiries."
Tabak was arrested on 20 January in Aberdeen Road, Cotham, where he was staying with Miss Morson. He answered the door at 05:55 and was "shaky and shocked" when he was arrested, the court heard.
The trial, which is expected to last four weeks, was adjourned until Tuesday.