A would-be thief was pulled to the ground by staff after he attempted to steal a bracelet from a Bognor jewellers on Sunday afternoon.
Police said a man entered H Samuels Jewellers, in London Road, Bognor, and snatched a gold bracelet that he had asked to look at.
The man ran off but a member of staff chased and caught him and retrieved the bracelet before the man ran off empty-handed, police have confirmed.
Emre Sen, who works opposite at the Clockhouse Café, said he ran out to help hold the man down after he heard a shop assistant shout for help.
Police said the man threatened to injure the staff member and she backed away while he ran off empty-handed, accompanied by a woman who had waited outside the shop for him.
An H Samuels spokesman said: “Our efforts are currently focused upon ensuring the welfare of our staff and we’ll be spending time with each of them to offer them counselling following this incident.”
Anyone with information can contact Sussex Police at www.sussex.police.uk/appealresponse or call 101, quoting serial 879 of 12/08.