PC jailed for sexually assaulting girl on duty and superimposing his face onto child abuse images

A police officer who assaulted a vulnerable young girl while on duty and superimposed his face onto child abuse images has been jailed for nine years.

Dean Dempster, 35, who was a response officer for Greater Manchester Police (GMP) based in Oldham at the time, sexually touched the child while responding to a disturbance in Oldham on 29 December 2023.

He was arrested the following day at work following a discussion about a formal complaint against him, and his personal phone and work phones were seized.

It later became apparent that before his arrest that morning, Dempster had deleted some material and applications from his personal mobile phone.

A search was undertaken at his home and a number of items were recovered, including another iPhone, a bundle of four pairs of folded children’s underwear, shredded underwear in a bag, a disc of images, and two hard drives.

Dempster’s mobile phone and iPad were found to contain 104 indecent images of children graded as category A – the most serious – including 30 pseudo images of that level as well as 440 category B images, including 129 pseudo images, and 2,472 category C images, including 39 pseudo images.

A large number of the pseudo images had been superimposed to depict Dempster with children.

The examination of his devices suggested that Dempster had been downloading indecent images of children from 15 December 2021 to 29 December 2023.

Further analysis of his internet usage revealed Dempster had been searching for children’s feet, and websites were accessed in December 2023 which contained content involving the feet of children.

Dempster was sacked by GMP following an accelerated misconduct hearing in May 2024.

He previously pleaded guilty to one count of sexual assault on a child under 13, six counts of making indecent images of children and two counts of misconduct in public office.

The prosecution followed an investigation by GMP’s Professional Standards Directorate directed by the Independent Office for Police Conduct.

At Liverpool Crown Court today, Dempster was sentenced to nine years' imprisonment, and must sign the sexual offenders' register for life. 

Malcolm McHaffie, Head of the Crown Prosecution Service’s Special Crime Division, said: “Dean Dempster’s actions were abhorrent, and he betrayed the trust placed in him as a serving police officer.

“The sexual assault took place while he was on duty, and there is no doubt that the victim has been deeply affected by being targeted by someone in authority.

“Subsequent searches of Dempster’s devices and his home address revealed further deplorable offending, and he is now facing the consequences of his actions.

“The Crown Prosecution Service will not hesitate to bring charges against those who abuse their position and target young people in such a reprehensible way.”