A drug addict killed a police dog handler thrown from a stolen taxi into a concrete bollard, a court has heard.
PC Ged Walker received fatal head injuries
David Parfitt, of Nottingham, ignored pleas to stop as PC Ged Walker was dragged 100 yards along a street in Bulwell, in Nottingham, in January.
Mr Parfitt, 26, of Wareham Close, denies murdering the 42-year-old father of two, who died in hospital two days after the incident.
The trial at Birmingham Crown Court is expected to last two weeks.
The court was told the defendant was being hunted by police, including PC Walker.
He had abandoned a stolen Vauxhall Astra in a pub car park when he was spotted by a plain clothes patrol.
Mr Parfitt called a taxi and when it arrived, he ran to the vehicle and leapt into the driver's seat.
The taxi driver jumped into the passenger seat and PC Walker went to the driver's door as the defendant drove away, the court was told.
The prosecution allege that the drug addict covered the keys with his right hand to stop either of the men turning off the engine.
They claim he then fled the scene, hiding in a house before concocting a story about doing some painting work.
The court was told he was eventually arrested in Fenton Drive the following day by officers who found him hiding in the loft.
Peter Joyce QC, prosecuting, told the jury: "When you listen to the evidence please be as cool and as calculating and as cold about it as he was on the day he killed Mr Walker."