phone records link a man accused of torturing and killing Lynda Spence to the DIY store where he allegedly bought items to clear up after the crime, a court has heard.
Dominic Kirsten, 45, a telecommunications analyst, said a mobile used by Colin Coats was recorded at a B&Q shop in Paisley on May 25, 2011.
Coats is one of four men on trial for the murder of Ms Spence, a Glasgow financial adviser who disappeared in April 2011.
Coats, 42, David Parker, 38, Paul Smith, 47, and Philip Wade, 42, deny abducting Ms Spence, torturing her for up to a fortnight and then killing her.
Prosecutors claim the men cleaned the flat where she was allegedly held in West Kilbride, Ayrshire, and replaced flooring to cover up the crime.
They are accused of buying floorboards, nails, paint and other items from B&Q in Renfrew Road, Paisley, on May 25.
Mr Kirsten told the High Court in Glasgow that a phone identified as belonging to Coats is "consistent with being at that location" on the given date.
Ms Spence, 27, was allegedly abducted on April 14, 2011.
Phone data showed that from April 15 to April 20, mobiles identified as belonging to Coats and Wade were "cell-sited" in the late morning or the afternoon in an area consistent with West Kilbride and Meadowfoot Road in the town, where it is claimed Ms Spence was held, Mr Kirsten said.
The witness is a specialist in mobile phone cell-site analysis with the company Forensic Telecommunications Services.
He explained to the jury that when a mobile is used for texts or calls it connects to a local cell site and information is stored that can be used to give its whereabouts.
The technology cannot pinpoint a mobile to a specific location, he said.
Gary Allan, QC, defending Wade, asked Mr Kirsten: "Although calls might show up at the West Kilbride mast ... might it be that the phone was somewhere else and the call or text had been diverted from its local site to the West Kilbride one?"
The witness said that situation could arise, but it was very rare.
He agreed with the QC that it is not possible to identify the phone user from data records.
Mr Allan said: "All we're talking about is a handset being in a particular location at a particular time."
Derek Ogg QC, defending Coats, will cross-examine Mr Kirsten today.
The case continues.