William O’Reilly, 44 and of no fixed address, entered the Sainsbury’s store in Suttons Lane in August to buy cigarettes and matches but didn’t have enough money with him.
After staff refused to serve him, he turned around and produced a handgun and demanded the till be opened.
He then produced a Stanley knife and threatened to slash the workers in the neck if money wasn’t handed over.
A member of staff tackled O’Reilly to the ground and detained him until police arrived.
In September, O’Reilly pleaded guilty to robbery, possession of an imitation firearm whilst committing a Schedule 1 offence and threatening a person with an offensive weapon in a public place.
He has been jailed for 10 years and four months at Snaresbrook Crown Court.
Officer in the case, DC Shona Wilkinson from the Met’s Flying Squad, said: “I would like to pay tribute to the victims, who showed immense bravery in tackling O’Reilly, during what must have been a terrifying ordeal.
“O’Reilly is a career criminal and I am pleased that he now faces a substantial period in prison.”
Tags: Hornchurch
