A mother and her two young daughters were threatened by a knife-wielding robber as they walked through a Berkshire nature reserve.
The woman was approached by the man in The Millie, Britwell, Slough, who made off with her bag and one of the girl's school bags.
Police have only just released details of the robbery, which happened at about 1600 BST on 15 October.
Patrols have been stepped up in the area to reassure residents.
Jill Martindale, of Thames Valley Police, said: "Although they were not physically hurt, the woman and her daughters were left very shaken by the incident."