A former Metropolitan Police undercover officer has told a public inquiry that his conduct while infiltrating left-wing groups in London during the 1990s was “cruel” and known to senior officers.
Mark Jenner, who used the undercover identity Mark Cassidy, was a member of the Special Demonstration Squad. The unit is under examination by the Undercover Policing Inquiry, which is assessing allegations of systemic misconduct. His evidence has renewed focus on the SDS undercover officer inquiry and the practices it is examining.
While deployed, Mr Jenner entered into a five-year sexual relationship with a school teacher known as Alison, who was among those he was tasked with monitoring. At the time, he was married with children. The inquiry heard that he moved into her flat, travelled abroad with her and attended family events, which he said assisted his cover.
Mr Jenner said he had been recruited in part because he was married and viewed as a “family man”. In 1995, he was sent to infiltrate the Colin Roach Centre in Hackney, a venue formed by a local trades union, where he met Alison and later began living with her. She was unaware that he was a police officer.
He described taking holidays with her to destinations including Thailand and Amsterdam, paid for using money from a joint account he held with his wife. He also spent time with Alison’s family and friends, activities which he said strengthened his credibility among activists.
His wife, referred to as S, previously told the inquiry she had agreed to his undercover role but believed he was targeting terrorists and had no knowledge of the relationship. Mr Jenner told the inquiry: “I thought financially we’d be secure and it would be a better future.”
“It was a hell of a strain and on my mind all the time,” he said, adding: “I tried to blank it out.”
“The thought of deceiving her [his wife] above everybody else was an absolute abhorrence,” he said.
He told the inquiry he loved his wife but accepted he was a largely “absent father”, saying “personal gratification and a police career took precedence”. Asked why the relationship with Alison continued for so long, he said it helped him “maintain his cover” and boosted his standing within activist groups. These admissions form part of the evidence now being considered by the SDS undercover officer inquiry.
Mr Jenner said his cohabitation with Alison was known within the SDS and had become an “open secret”. He told the inquiry that senior officers were aware of the arrangement. His supervising officer, DCI Bob Lambert, also had relationships while undercover, including one in which he fathered a child.
Documents shown to the inquiry included a 1996 performance review by DCI Lambert, describing Mr Jenner as a “phlegmatic officer who remains calm in the face of danger” operating in a “dangerous and hostile environment”. A Special Branch record showed Mr Jenner received a commendation in September 2000, praising his acceptance of work demands over “domestic arrangements”.
After his identity was exposed in the media in 2011, Mr Jenner said he lied during an internal interview at Scotland Yard. “I was trying to hold out for as long as possible,” he told the inquiry. In a later interview in 2013, he said: “My actions when working undercover for SDS were with the knowledge and approval of my line managers. Whatever I did within the SDS was professional.”
He told the inquiry: “You could do pretty much do what you want apart from kill anybody, it would be covered.
“We were supported by secrecy and the management and the whole structure around SDS.”
It is believed at least 50 women were deceived into relationships by SDS officers over several decades. After Mr Jenner’s evidence, Alison said she was “very pleased” that he acknowledged the relationship was widely known. “So much of what Mark Jenner said was very shocking,” she said, adding that his claim the relationship was necessary for cover was particularly disturbing.
The Metropolitan Police has apologised “unreservedly” for the harm caused, stating: “These relationships were abusive, deceitful, manipulative and wrong.” It said undercover policing had since undergone significant reform with clearer ethical rules.
The SDS undercover officer inquiry is continuing and is expected to resume in the new year.
