PC who sexually assaulted six-year-old girl jailed

Thousands of images were found on PC Dean Dempster's devices

A "depraved" PC who sexually assaulted a six-year-old girl while on duty and superimposed his face on to child abuse images has been jailed.

Former Greater Manchester Police (GMP) officer Dean Dempster, 35, pleaded guilty to sexually assaulting the child when responding to a disturbance in Oldham in December 2023 and six counts of making child abuse images.

Thousands of indecent images of children were discovered when his devices were seized, with more than 100 graded as category A – the most serious.

He was jailed at Liverpool Crown Court for nine years and ordered to sign the sex offenders' register for life.

Dempster, of West Didsbury, Manchester, joined the force in 2021 and was one of three officers responding to a domestic incident involving an adult and children on 29 December 2023.

It was while taking an account from a six-year-old girl, away from colleagues, he sexually abused her, GMP said.

He was arrested the next day and investigated by GMP's professional standards directorate for any further offending, under the direction of the Independent Office for Police Conduct.

Greater Manchester Police say the force "wasted no time dismissing" Dempster

A search of Dempster’s home revealed further serious offending include making of indecent images of children, the Crown Prosecution Service (CPS) said.

Four pairs of folded children’s underwear, shredded underwear in a bag, a disc of images, and two hard drives were also seized along with his devices.

Dempster’s mobile phone and iPad were found to contain 104 indecent images of children graded as category A, 440 category B images and 2,472 category C images.

The CPS said they had been downloaded from December 2021 until 29 December 2023.

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

Images of children, taken from his body-worn video camera from the December 2023 incident and another incident in 2022 were also found on his mobile phone.

The victims of both families have been made aware and kept updated, the force said.

Dempster was sacked at an accelerated misconduct hearing in May.

'Despicable betrayal'

Deputy Chief Constable Terry Woods said: "I am angry and appalled at this abhorrent abuse of responsibility and trust.

"We commend the bravery of this young victim for coming forward.

"We apologise to her family and know nothing will ever undo the harm Dempster has caused to his victims."

He said Dempster, who also admitted two counts of misconduct in public office, "represents the very worst of society".

"He is not a police officer; he is a child sex offender, a criminal, and he has no right to be near police uniform or serve the public," he said.

"Dempster is a depraved exception who we have wasted no time in dismissing and disowning."

At Dempster's disciplinary hearing, Chief Constable Stephen Watson, said: "It is this most egregious breach of trust of an innocent young child that is the most upsetting aspect of this case.

"I consider this case to be among the most distressing ever presented to me, such is the despicable betrayal of all that is inherent in being a decent police officer."

An NSPCC spokesperson said: "As a police officer, Dempster’s role was to protect the vulnerable.

"Through his training and work he would also have been aware of the profoundly harmful impact that child sexual abuse can have on victims.

"Instead he sexually abused a young girl whilst on duty, took indecent photographs as a responding officer and downloaded thousands of child sexual abuse images of children, all of which was a devastating breach of trust that was placed in him."