Police on Merseyside are trying to find a thief who took a paramedic's car while he was treating a patient, and then drove at him.
The paramedic had been called to an accident at the junction of Woodchurch Road and Balls Road East in Birkenhead at 1040 BST on 28 July.
The man got into the unmarked response vehicle, an Audi RS4, and knocked down the victim as he tried to stop him.
The paramedic suffered minor injuries to his arm, police said.
The Audi was recovered with all of its contents soon afterwards, in Oxton Village, without its keys.
It had to be taken off the road for several days, while its locks were changed.
Det Con Sarah Casement, of Merseyside Police, said: "An attack such as this, on a paramedic who was helping an other at the scene of a traffic collision, is despicable.
"Incidents such as this are taken very seriously and I would appeal to the public for their help in catching whoever was responsible for this crime."
Derek Cartwright, director of emergency service at North West Ambulance Service, added: "I am at loss to understand the reason behind mindless actions such as this, against a service which exists purely to help people."