Two men have been arrested on suspicion of murder after PC Dave Phillips was struck by a car and killed during a pursuit in Merseyside.
The 34-year-old died from internal injuries after being hit by a pick-up vehicle that mounted a central reservation in Wallasey on Monday.
The married father-of-two had been trying to stop a Mitsubishi Challenger, which was taken from an estate agents in Birkenhead.
The men aged 18 and 30 are in custody.
Officers have also executed warrants to carry out searches at four properties in the Oxton and Wallasey areas as part of the investigation.
PC Phillips had been responding to reports of a burglary in Woodchurch Road, Birkenhead.
He and a colleague had been attempting to stop the vehicle using a tyre-puncturing “stinger” device at 02:10 BST.
Fellow officers tried to save his life before he was rushed to hospital, but he died shortly after arrival.
The red pick-up vehicle was found abandoned in Corbyn Street, Wallasey at 02:55.
Det Ch Spt Paul Richardson appealed for anyone with information to contact the force.
Merseyside Police Federation has set up a memorial fund in tribute to PC Phillips for his wife Jen and daughters Abigail, seven, and Sophie, three.