This is the moment a gunman’s attempted robbery on young children and families was foiled by a waiting mother – who turned out to be an off-duty armed policewoman.

Dramatic security footage shows a suspect named as Elivelton Neves Moreira, 21, approaching the crowd with a gun outside a private school in Sao Paulo.

But his attempted crime backfired when military police officer Katia da Silva Sastre, 42, pulled out her own weapon and unleashed three shots.

The video shows Moreira, who later died in hospital, falling backwards and clutching his chest before Sastre shoves him on to his front with her foot having thrown her handbag aside on Saturday morning.

Officer Sastre is being hailed a hero for her act of bravery and was honored in a ceremony by Sao Paulo Governor Márcio França on Sunday.