A police officer - who was later exposed as a violent serial rapist - passed vetting checks to join the force despite having two reports of criminal behaviour against women on his record, BBC Disclosure can reveal.
Alan Greer was investigated by police in 2002 and 2005 for making inappropriate phone calls to women, with one case resulting in a formal police caution.
He was accepted into Strathclyde Police in 2009, despite vetting staff being aware of his previous offending.
The revelation comes a month after Police Scotland told the BBC there had been no "missed opportunities over the years" to identify Greer's offending sooner.
In response to further questions from the BBC, Police Scotland moved to clarify its earlier comments.
It said it had "provided answers to questions relating to Alan Greer's offending during the course of his police career" and did not believe it had been answering questions about his police vetting record.
Greer had been a police officer for 17 years when he took his own life in May, just days after a police raid on his home as part of an investigation into offences dating back to 2012.
Last month, the BBC revealed he had committed a series of attempted murders or serious sexual assaults, including raping a vulnerable woman just hours after meeting her on duty.
It has since emerged that Greer had contact with hundreds of sex workers throughout his police career, and violently assaulted many of them.
It is also understood he took inappropriate photographs of female colleagues while working in police officer safety training.
Police Scotland has so far identified 15 of Greer's victims, amid fears the true number is far greater.
When the BBC revealed the story last month, Assistant Chief Constable Lynn Ratcliff was asked if there had been any opportunities to stop Greer's offending earlier.
She said: "At this point, and we will keep it under review, there is nothing to suggest that there have been any missed opportunities over the years."
When pressed if there were no missed red flags, she said "At this stage, we've got no evidence to suggest that is the case…"
Asked if there were any vetting issues in relation to Greer, ACC Ratcliff said the vetting landscape is "markedly different" today, that Greer would not have passed current vetting checks, but she did not offer further details.
The assistant chief constable added that officers were now subject to annual integrity testing and routine re-vetting.
A BBC Disclosure investigation can now reveal:
Greer was investigated in 2002 by Strathclyde Police for making inappropriate phone calls to a woman in Glasgow. The case was reported to the procurator fiscal but no action was taken
The Metropolitan Police issued Greer with a formal police caution in 2005 after he was again caught making inappropriate phone calls, this time to a woman he knew in London
Four years later in 2009, Strathclyde Police accepted Greer into the force despite being aware of at least the formal police caution issued by the Metropolitan Police
Police Scotland has now confirmed that Strathclyde's vetting unit in 2009 was aware of Greer's 2005 police caution when he was applying for the job.
A partial paper vetting record exists for Greer and the caution is referenced.
The force said it was unclear whether the 2002 offence formed part of the interview process, or was known by vetting staff.
Sources say this 2002 "adverse trace" would "absolutely" have been discoverable on Greer's record.
A Strathclyde Police Standard Operating Procedures handbook for 2006 states: "The force should not recruit people with cautions or convictions, which may call into question the integrity of the applicant or the force."
A police source told the BBC: "Two reported crimes related to women before he joined should have been raising all sorts of alarm bells.
"He was clearly a menace from the off and should never have been allowed near a uniform to abuse his position."
Craig Naylor, chief inspector for HM Inspectorate of Constabulary in Scotland (HMICS), led a review into Police Scotland vetting processes in 2023.
He said the vetting landscape in 2009, though not as strict as today, should still have meant Greer's past would preclude entry to the police.
He said: "My view is that he should never have got in at that point, and my view is that in the intervening period, I'm surprised that something didn't come up about that.
"When I've run vetting in the past, he would not have got in."
Asked by the BBC if these were missed opportunities to stop Greer joining the police, Naylor answered, "Yes".
A Police Scotland spokesperson said: "We have been completely open and transparent around information which can be shared in relation to the ongoing investigation into Alan Greer.
"During an interview with the BBC on 20 July 2026 we provided answers to questions relating to Alan Greer's offending during the course of his policing career, which spanned almost 17 years.
"The investigation has not established any information during his career which could have resulted in his criminal behaviour being identified at an earlier stage.
"The recruitment and vetting process carried out by Strathclyde Police prior to Alan Greer joining in 2009 will form part of an independent and external review by the National Police Chiefs' Council.
"Our absolute priority throughout this investigation is to support victims. As work continues to identify and support everyone affected by this case it is imperative that we do not disclose any information which could be detrimental to that support."
The BBC has obtained a confidential briefing document about the case, "Operation Submarine", prepared by the investigation's SIO (senior investigating officer).
The document is dated 12 June this year, about four weeks before the BBC contacted Police Scotland over its intention to run a story about the case.
It is described as a "high level overview" into Greer's "significant serious sexual offending".
Point 3 of the document is headlined "Identified Criminality" and details of the 2002 and 2005 investigations are listed.
It states: "Within the current vetting regime, he would not have been granted Recruitment Vetting."
The document was provided to the Scottish government and the Scottish Police Authority (SPA), the oversight body tasked with holding senior officers to account.
Yet during a public board meeting of the SPA on 30 July, a week after the BBC broke the initial story, none of the SPA board put the details of Greer's vetting issue to DCC Alan Spiers, who was there in place of Chief Constable Jo Farrell.
Board member Chris Creegan asked DCC Spiers which of Strathclyde's previous vetting arrangements were of "particular relevance to this case and Alan Greer's own history" but did not press for an answer and no details of Greer's vetting record were disclosed.
The SPA told the BBC that only the authority's chairman Alistair Hay and chief executive Chris Brown, who were both present at the meeting, received the briefing about Greer's vetting - and that it had not been shared with Creegan.
It said operational briefings were not "routinely shared" with board members.
A spokesperson for the SPA said: "Three authority members raised a number of initial questions to seek assurance about the approach being taken, the impact on public confidence - and the assertion that significant changes to vetting regulations would mean an individual such as Alan Greer, would not be able to join policing today."
Following the review and in response to concern over high-profile vetting failures in England including the case of David Carrick, Police Scotland initiated a "historic data wash".
It was part of a vetting improvement plan "to identify any intelligence or allegations that needed further investigation".
The Anti-Corruption Unit (ACU) led the project, along with the force's vetting unit, and concluded: "No significant matters were uncovered that the force were not already aware of."
Police Scotland confirmed the data wash flagged nothing in relation to Greer.
Naylor told the BBC this was another missed opportunity to spot him sooner.
A police source told the BBC: "So the data wash was useless then? How can they say there were no missed opportunities to spot Greer sooner?
"The question is, how many more Alan Greers have they missed?"
Police Scotland added: "We have already stated publicly that the vetting landscape in 2026 is markedly different from that in 2009 and, under current arrangements, Alan Greer's application would not have progressed."
