In March 2017, the Metropolitan Police Service (MPS) established a new investigation, Operation Lynemouth, to review and reinvestigate alleged criminal offences arising from the 2014 mayoral election in Tower Hamlets.
The purpose of the new investigation was to assess and, where appropriate, investigate criminal allegations relating to electoral fraud and malpractice, or other criminal offences.
The Mayor's Office for Policing and Crime (MOPAC) asked Her Majesty's Inspectorate of Constabulary and Fire & Rescue Services (HMICFRS) to inspect the MPS's operation, providing interim assurance reports every quarter.
In September 2018, the MPS announced it had concluded Operation Lynemouth, and that it had not identified sufficient additional evidence or investigative opportunities to enable the Met to request the Crown Prosecution Service (CPS) to consider the charging of any individual in relation to offences of electoral fraud and malpractice arising from the 2014 mayoral election.
The final cost of the MPS investigation amounted to £1.7million, and involved up to 20 detectives and police staff.
The final HMICFRS inspection report was published today, Tuesday, 12 March.
The report acknowledged the work of the original police investigations, but found the policing of the election and the subsequent investigation lacked appropriate oversight and coordination, and that there was a lack of corporate responsibility, and insufficient training and resources for the original investigation. Importantly, the MPS should have better explained the reasons why no person was convicted of a criminal offence.
In relation to the 2017 reinvestigation (Operation Lynemouth), the report highlights the painstaking and thorough approach of investigators that achieved its objectives.
The MPS accepts the report's findings in full.
HMICFRS recognised that the Met and partner agencies have done much to improve processes and procedures in respect of policing future elections, but the MPS should never be complacent.
Seven areas were highlighted for ongoing consideration by the MPS.
Commander Stuart Cundy, who oversaw the investigation and the Met's improvements, said: "The MPS takes its policing responsibility of elections very seriously. We welcome the findings of the HMICFRS report and will carefully consider whether further action is needed in order to prevent failings in the future.
"The Met's own review and reinvestigation identified aspects of the original investigation where the MPS needed to learn - this included how we work with Returning Officers to police elections, the training and briefing of police officers, our engagement with prospective candidates and local communities and ensuring an accurate record is kept of all investigative enquiries.
"These areas of organisational learning were incorporated into policing plans for the local London elections, including the Tower Hamlets Mayoral Election held in May 2018.
"I have previously said that the Met could have been more open in its engagement with a number of directly affected key individuals and groups. Throughout the reinvestigation, detectives have maintained contact with a number of those individuals.
"Since 2014 we have taken significant steps to improve how we communicate with our partners and local communities, which includes a robust system for reporting allegations of electoral fraud and receiving feedback. Officers responsible for investigating electoral fraud and malpractice were enrolled on a new national training course. The MPS worked with local councils, external partners and an Independent Advisory Group before introducing a bespoke policing plan for the 2018 elections in Tower Hamlets.
"After an exhaustive police reinvestigation, the Inspectorate concluded the original investigation team had completed a great deal of work and reached the right decisions.
"I know some will remain concerned as to why the criminal investigation has not led to persons being convicted of a criminal offence. As explained in his judgment, Mr Mawrey QC was clear that the rules and procedures for the admissibility of evidence in an election court is quite different to criminal proceedings. In reaching its conclusion that there is insufficient evidence to seek any new charging decision for a criminal offence, our reinvestigation robustly considered all the evidence available."