A Northumbria Police officer has been jailed for life for carrying out sex attacks on vulnerable women he met while on duty in Newcastle.
Pc Stephen Mitchell had earlier been convicted of two charges of rape, three indecent assaults and six counts of misconduct in public office.
The 42-year-old, from Glasgow, who had denied all charges, was given two life sentences at Newcastle Crown Court.
He was told he will not be eligible for parole for at least seven years.
During a five-week trial it emerged Mitchell targeted vulnerable women, including heroin addicts and shoplifters, by offering to help them while they were in custody at Newcastle's Pilgrim Street police station and then asking for sexual favours.
He denied all the charges and claimed the 16 women who made complaints about his behaviour were liars.
Mitchell was cleared of nine counts of misconduct in public office, three of indecent assault and three of rape.
During the trial, the court heard Northumbria Police had disciplined Mitchell when it was discovered he had sex with a woman he had met as part of his duties, but he was not dismissed for the offence.
It also emerged he was accused of a serious sexual offence while he was still in the Army, but this was not revealed when he applied to join Northumbria Police.
Mitchell resigned when he was convicted and the force has said it will be seeking authority to apply for a forfeiture of his pension.
Temporary Deputy Chief Constable Jim Campbell offered his "unreserved apologies" to anyone who has been subject to criminal or inappropriate behaviour by Mitchell during his time as a serving officer.
"The public quite rightly expect that the officers and staff of Northumbria Police adhere to the highest possible standards of professional conduct and place immense trust in them," he said.
"Mitchell, acting alone for his own abusive purposes, completely abused this trust and is now where he deserves to be, behind bars for a considerable period of time."
Paul Simpson, from the Crown Prosecution Service, described Mitchell's case as a "one-off" and praised Northumbria Police for "rooting this man from the force".
He said: "The sentence imposed today reflects the gravity of his offending and recognises the danger he poses to women.
"I would like to pay tribute to the victims in this case.
"In giving evidence and re-living some of the darkest days of their lives they showed immense courage.
"Without them this prosecution could not have been brought."
Some of Mitchell's victims are now pursuing civil claims for sexual assault, false imprisonment and breach of human rights.
Sentencing, trial judge Mr Justice Wilkie said Mitchell presented such a danger to women that he might never be released from prison.
'Cowed and downtrodden'
He said the officer had broken the bond of trust that existed between the public and the police. Mitchell was a sexual predator who "ruthlessly exploited" his victims for his own pleasure and "degraded them repeatedly".
"You succeeded so well you were able to treat them as sex objects over a period of months, and in some cases, years," he said.
"So cowed and downtrodden by their experiences of life and by your influence were those seven women that they did not report what you had done until they were given the opportunity to do so by the police investigation into your activities years later."
He said Mitchell would serve at least seven-and-a-half years in jail before being considered for parole.
"Thereafter, you will only be released, if at all, if the parole board has concluded it is safe and in the public interest for you to be released on public licence," he added.
"That may not be for many years, if for ever."