An axe-wielding robber stole £50 from a chemist before fleeing up the A12 to Colchester.
The man entered Cole Cross Chemist in Hylands Parade, Chelmsford, at around 11.40am.
He threatened staff before escaping with the money in a white BMW car.
The vehicle was spotted on the A12 less than 30 minutes later, but it sped off when it saw a police car.
It is thought the BMW left the road at the Spring Lane junction, where it collided with a second car but did not stop.
The Essex Police helicoper was sent up after a man was spotted by police officers on foot near the Cowdray Avenue end of Harwich Road.
A BMW car was recovered in Round Close shortly afterwards.
- A Colchester man has been arrested on suspicion of robbery.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article