Police have released CCTV images of a man suspected of robbing two Newham bookmakers within the space of three days.
He struck first at a branch in Mary Rose Mall, Beckton, at about 4.40pm on April 15.
The man threatened staff that he would start shooting, though no firearm was seen, before escaping with a quantity of cash.
Then, on April 18 about 1.55pm a white man - believed to be the same suspect - entered a bookies in High Street South, East Ham.
He again threatened to shoot but no weapon was seen. On this occasion he left empty-handed.
Investigating officer Det Con Phil Cross, said police were appealing for anyone with information in Newham, Barking and Dagenham and Tower Hamlets to come forward.
To assist, contact 020 8345 4255 or Crimestoppers anonymously on 0800 555 111.
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