An armed diplomatic security officer who abandoned his duties for extra-marital sex has been sentenced to nine months in prison.
Ricci Giff's job as a motorcycle officer included guarding Downing Street and anti-terrorism work. He left his London patrol area, including some of the UK's most "high-profile targets", three times in late 2011 to meet Melissa Ramsden.
One of the meetings was five miles from his patrol area. Others took place during night shifts at her flat in Kilburn, when he told his colleague he was going to meet a friend in Paddington.
One time the 38-year-old's unattended police motorbike was found outside her flat by officers who raised the alarm in case he was in danger, only to see him come out and ride off.
Giff, of Sandy, Bedfordshire, is married with two young children and has 15 years police experience. He admitted three counts of misconduct in a public office at an earlier hearing, but looked visibly shocked when he was jailed.
Southwark Crown Court heard he left his radio on while he was with Miss Ramsden, but Judge Anthony Pitts said: "It probably in fact made it quite difficult for you to respond quickly if you were in the middle of making love to her during these periods.
"That is a job of some responsibility and importance.
"Of course, most of the time there would not be an emergency. But you are there as part of a unit in a designated area, on call ready to respond immediately to what may be an incident of extreme urgency. That is your job."
The court heard today he met Miss Ramsden, 37, on other occasions, including one December 2011 shift when he was protecting Downing Street - but they were allowed because they happened during breaks in his 12-hour shifts.
After the Downing Street shift he went to her flat and it was then that she posed for photos, including one in which she was naked apart from Giff's uniform utility belt, containing his gun and Taser.
Ms Ramsden worked for the Israeli tourism office - part of Giff's patrol route. She killed herself in December 2011.
Giff was not implicated in her death, the court heard, photographs and text messages found on her phone by investigating officers revealed their relationship.
She had a history of depression and was found dead at her flat, days after their last meeting.
She sent him a text message the day before, thanking him for "being loving".
Claire Howell, prosecuting, said: "There were large periods of time where he (Giff) was trusted to be within the patrol area ready to respond if required.
"He was fully armed and supposed to be part of a high-profile unit guarding high-profile targets.
"He, more than anyone else, would have appreciated the potentially catastrophic results if anything had happened and there was a delay in the response time."
Richard Atchley, representing Giff, said he apologised for his actions, especially to his wife and colleagues for letting them down.
He said Giff had had a difficult childhood and could have led a life of crime but opted instead to join the police, where he had an exemplary career until his relationship with Miss Ramsden.
This career was over because of his "foolhardy" actions, he said.
"He has paid a high price for his foolish and unprofessional behaviour," he added, saying Giff never missed a check during his motorcycle patrol in the capital.
The court heard that at the time of the affair Giff was going through a "baby blues" period with his second wife.
Giff remains a police officer pending disciplinary proceedings, he said, which will see him sacked.