A FORMER decorated detective who had sex with a woman at a police station and let her handle his gun will be sentenced on Thursday.

media_camera Mark Garner in 2004.

Mark Garner had earlier pleaded guilty to two counts of misconduct in office while he was a sergeant on the NSW north coast.

His legal team argued on Wednesday that Garner, who appeared before Sydney’s District Court, was an otherwise “conscientious and devoted officer” and had been suffering mental health issues at the time of the offences.

The 50-year-old cried when he gave evidence in court last week, recounting his downward spiral from the 1990s, when he received courage and bravery awards, to after 2007, when he was drinking up to four bottles of wine a day.

It was in this low state in 2011, he told the court, that he met a woman, who cannot be named.

She had visited Kingscliff station to make a complaint about an alleged assault.

“She would come into the police station where we would talk. We started building a friendship ... then it developed into something more,” Garner said.

He said he had not been intimate with his wife for some time.

“At that time, I believe I was vulnerable ... all of a sudden this young, pretty girl comes along and takes an interest in me,” he said.

The court heard that in September 2011, Garner let the woman handle his Glock pistol and had sex with her at the station.

He also admitted to inappropriately accessing police files to gain details of the address of a person who might have taken a laptop owned by the woman.

Garner said the laptop contained photos of the pair in an “intimate session”, which would have been embarrassing and possibly career-destroying if they got out.

He admitted to the court he had tried to assist in her plan to break into the person’s home and retrieve the computer.

The court heard he had been diagnosed with post-traumatic stress disorder in 2012, after years of investigating serious crimes.

Garner, who now works as a night manager at a club, admitted he had disgraced himself and his family.

His matter will return to court for sentencing on Thursday before Judge Ross Letherbarrow.