[9] Allen had always been interested in the police and in 1968 saw a recruitment advertisement in the newspaper, applied, and was selected.

"[10] After training at Peel House[11] for 13 weeks,[12] she was posted to Fell Road police station in Croydon, where she lived, on 29 April 1968, aged 29.

[13] She experienced more prejudice from the black community than from her colleagues or from white people in Croydon,[9] and was met largely with curiosity and considerable interest from the media, although the Metropolitan Police did receive some racist mail about her appointment.

[4][9] The threatening and abusive letters she received when she started working at Fell Road made her consider whether she wanted to remain in the force.

[14][15][16] After a year in Croydon, she was posted to the Missing Persons Bureau at Scotland Yard for a while before being transferred back to the beat at Norbury police station.