A policeman has been jailed for life after being convicted of raping and sexually assaulting vulnerable women. Pc Stephen Mitchell preyed on women he met while on duty from his base at Pilgrim Street police station in Newcastle. He was given two life sentences at Newcastle Crown Court and told he would not be eligible for parole for at least seven-and-a-half years. Mitchell, originally from Glasgow, raped and sexually abused heroin addicts, shoplifters and a disabled teenager by offering them help while in custody, then later demanding sexual favours. Mitchell, 42, formerly of Whitley Bay, North Tyneside, told one of his victims that if she complained, "no one would believe a junkie". During a five-week trial in December, the Pc claimed he was the victim of a conspiracy hatched by the criminal underworld and labelled his accusers liars. But after nearly a week of deliberation, a jury convicted him of raping two women and carrying out three further indecent assaults. Mitchell was convicted of two rapes, three indecent assaults and six counts of misconduct in a public office against seven female victims. Sentencing, trial judge Mr Justice Wilkie said Mitchell presented such a danger to women that he might never be released from prison. 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". He said: "You succeeded so well you were able to treat them as sex objects over a period of months, and in some cases, years. 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. That may not be for many years, if for ever."