A reward of up to £20,000 has been offered in the hunt for robbers who shot a Chingford shop owner as he defended his business.
CCTV of the incident on October 31 has been released for the first time in an attempt to trace two men.
The images show two men entering the Show Supermarket in High Street, Plaistow, at 11.45pm on October 31 last year.
One man threatened 51-year-old shop owner and father-of-three, Abbas Boran, from Chingford, and his 40-year-old shop assistant with what appears to be a sawn-off shotgun. and demanded cash.
The shop owner and assistant resisted the robbery by grabbing and attempting to bat away the gun.
Both robbers then flee the shop empty-handed, making off towards Winkfield Road.
The shop assistant and the shop owner chased after them and Mr Boran was shot in the chest at close range.
The CCTV shows him staggering back to the shop, helped by the shop assistant.
Mr Boran fell into a two-week coma and suffered what are described as life-changing injuries, which have had a serious impact on his quality of life.
The shop assistant was hit in the leg and abdomen by fragments of the bullet and has made a full recovery.
One robber is described as wearing dark trousers and a dark baseball cap under a dark, hooded jacket, which features a logo on the top of each arm.
The second is described as also wearing dark trousers, and a dark jacket with a white strip down the centre of the front.
The reward, offered by the Association of Convenience Stores and charity Crimestoppers, is for information that leads to the arrest and conviction of the people responsible for what is being treated as attempted murder.
Investigating officer, Detective Sergeant Gary Ferguson of the Met's Flying Squad, said: "These men are dangerous and we need to find them urgently.
"Although suspect one tried to cover up, you can see most of his face in the CCTV footage. His face is distinctive. We are sure that someone who knows this man would recognise him from the CCTV. Take a good hard look at his face - do you know him?
"Alternatively, were you in the area on Halloween last year and remember seeing men fitting these descriptions at around quarter to midnight? Was one of them was holding something that could have been a sawn-off shot gun? Where had they come from? Where were they going? If you know anything, call us now."
Mr Boran's 27-year-old daughter said: "My dad is an honest, hard-working man. He has run the Show Supermarket for 14 years and is well known to the local community as a friendly person.
"On the 31st of October last year, his life changed when he tried to defend his livelihood from armed robbers. He was bravely chasing two armed men away from his shop when one of them shot him in the chest.
"They ran off, leaving him bleeding in the street.
"He was taken to hospital where he fell into a coma that lasted over two weeks. My family and I were sick with worry, not knowing if he would live.
"We are lucky that he survived. But since then he has suffered numerous health problems as a result of the assault. He is afraid and unable to return to work.
"If anyone recognises the men in the CCTV or has any information about the attack on my dad, please come forward. We need closure on this and we are afraid of the threat these men pose to others while they are out free."
Anyone with information on the incident is asked to call Crimestoppers anonymously on 0800 555 111 or call the Flying Squad directly on 020 8345 4226.