A Brighton police officer tackled and arrested an armed man three days after he held up a bookmakers.
PC Christian Rohman swung into action when Raymond Jacklin, 60, pointed a pistol at him at point-blank range.
The Sussex Police officer later learnt that the weapon was an imitation firearm, although he had no idea at the time that it was a fake.
Inspector Robert Leet, of the Brighton and Hove Division Neighbourhood Response Team said: “PC Chris Rohman’s brave and selfless actions enabled a dangerous offender to be apprehended swiftly and safely.
“His courage and quick thinking meant that Jacklin could be brought to justice at the earliest opportunity and help make the city an even safer place.
“This is a good example of the unexpected dangers which police officers can face and the professionalism in which they carry out their duty.
“Chris is a real credit to us and we should all be proud of his contribution here.”
He made the arrest in Lewes Road, Brighton, on Saturday 23 January.
As a result Jacklin, of no fixed address, has appeared at Hove Crown Court and been sent to prison for five years
He was jailed for robbery, having an imitation firearm in a public place and having an imitation firearm with intent to commit an offence.
Jacklin was caught on CCTV using the fake pistol to carry out a robbery at Ladbrokes in Market Street, Brighton, on January 20.