The trial of Simon Richardson, accused of murdering Stretford Grammar headteacher Michael Mullins, continued at Minshull Street Crown Court with evidence about the Volvo allegedly used in the incident.
Mr Richardson, 35, denies murder, manslaughter and dangerous driving. He is alleged to have run over Mr Mullins as he cycled home, then dragged him under his car for 1.3 miles (2.2km) before Mr Mullins died on a grass verge on Wet Gate Lane in Lymm.
Volvo and witness evidence
Detective Sergeant Tricia Soloman returned to the witness box and confirmed the last time the Volvo was driven by Mr Richardson was the night before the incident, after which it was swapped for a silver van. The Volvo was described as of 'obvious interest' to police.
At 7.34pm, police saw the Volvo in Altrincham, driven by another man named Aaron Parry. It was seen entering the Asda car park, and officers spoke to Mr Parry and a female passenger. The Volvo was taken into police custody.
The court heard that police were aware of the importance of the silver van. Mrs Justice Brunner KC told the jury that Gabrielle Debotte will give evidence tomorrow, rather than today, and the court will instead hear evidence regarding the alleged dangerous driving on April 21.
GPS and Apple Watch data analysis
GPS expert Dr Chaz Dixon was cross-examined by defence barrister Jaime Hamilton KC. Dr Dixon confirmed his expertise relates to navigation, timings and 'significant aspects of communications'. He was given data from police in the form of a spreadsheet.
Looking at the Apple Watch worn by Mr Mullins, Dr Dixon said data was recorded at one-second intervals, working like a speed camera. He noted a 23-second pause in data at 6.07pm, around the time of the collision, and described it as an 'unusual gap'. He said the watch not recording could indicate something interfering with its signal.
The court heard that data showed Mr Mullins left Stretford Grammar School, travelled through Stretford, Urmston, Flixton, Carrington, and towards Lymm. There was a 28-second gap in the watch data, which Dr Dixon said was 'very unusual' and likely a direct result of the collision.
Medical evidence and cause of death
Earlier, Dr Terrence McGloughlin, a consultant in emergency medicine, gave evidence. He said Mr Mullins survived the initial impact and remained 'physiologically alive' during the dragging and at the roadside on Wet Gate Lane.
Dr McGloughlin said Mr Mullins suffered a 'crush' injury to his chest and thorax, and that 'widespread and deep friction' to his left side led to significant blood loss. He described the 999 call from a motorcyclist who said Mr Mullins was breathing 'only just', which he interpreted as 'the last gasp of life, before death'.
Pathologist Dr Jamie Robinson previously concluded the cause of death as 'multiple injuries', including severe blunt force trauma to the chest, extensive rib fractures, contusions to both lungs, and significant blood loss. He confirmed it was possible that death was caused by the dragging.
The trial continues at Minshull Street Crown Court.
