The West Midlands Police and Crime Commissioner, Bob Jones, has backed a father's campaign calling for a public inquiry into the conduct of a police investigation after his son was among three men killed in the Birmingham riots in 2011.
Eight men were cleared of the murders of Haroon Jahan, Shazad Ali and Abdul Musavir in Winson Green.
Yesterday, the IPCC found that police had mishandled the murder investigation.
Tariq Jahan is now calling for more high-profile support for his campaign.
The Deputy Chair of the Independent Police Complaints Commission, Rachel Cerfontyne, has told ITV News Central Political Correspondent, Alison Mackenzie, that DI Khalid Kiyani would have had a case to answer for gross misconduct if he was still serving with West Midlands Police.
It follows an investigation by the police watchdog which said the handling of a criminal investigation into the deaths of three men in the summer 2011 riots in Birmingham was mishandled.
West Midlands Police say the force has taken steps to strengthen some of the procedures it has with other criminal justice partners.
It follows a report by the IPCC which said the handling of a criminal investigation into the deaths of three men in the summer 2011 riots in Birmingham was mishandled by the force.
Once again, I along with the rest of the force extend our deepest sympathies to the family and friends of the deceased who continue to grieve for their loved ones.The independent investigation shows that no officer from West Midlands Police deliberately misled the trial at Birmingham Crown Court.
The investigation found that in trying to encourage witnesses to come forward to help the triple murder investigation DI Khalid Kiyani offered eye-witnesses immunity from prosecution for public order offences.
This is clearly outside of the remit of any police officer and as the IPCC state, was a reckless act. DI Kiyani compulsorily left the force in 2012 as a result of the A19 regulations that required officers with 30 years’ service to retire and therefore cannot be the subject of any police disciplinary proceedings.
The investigation found no evidence that Senior Investigating Officer Anthony Tagg had authorised or even knew of the offer made by DI Kiyani.
However, during the court case, when he became aware of this immunity offer, the IPCC investigation concludes that he should have passed this information on with greater clarity.
The report recommends that the force reminds DCI Tagg of his SIO responsibilities through management intervention. This has been completed. The force has already taken steps to strengthen some of the procedures we have with other criminal justice partners. The learning from this investigation has been built into future training for all senior investigating officers.
– Assistant Chief Constable Gary Cann , West Midlands Police
While our investigation found that Detective Chief Inspector Tagg should have been more forcible and clear in advising prosecution Counsel of the immunity issue, he did not intend to deceive in his evidence provided at Crown Court. We found no evidence to corroborate the assertion that DCI Tagg knew of or sanctioned the offer of immunity prior to it being given at a public meeting by DI Kiyani.
DCI Tagg may have told Counsel about the immunity issue, but on the basis he should have done so with greater clarity and conviction the IPCC recommended management intervention to remind him of his responsibilities as a senior investigating officer.
The murder investigation was a complex, high profile one and it was vital that it was carried out in a way that could command the confidence of all communities in Birmingham. While we cannot say what impact this issue had on the trial or the verdict, the bereaved families publicly placed their faith in the criminal justice system but they understandably feel that they have been failed by the system they trusted.
The IPCC said there was "no case to answer" for misconduct against the man who led a triple murder investigation arising from the riots in Birmingham in August 2011. Detective Chief Inspector Anthony Tagg was in charge of the criminal investigation.
However, the police watchdog did say the family liaision officer, Detective Inspector Khalid Kiyani, who retired in October 2012, "would have had a case to answer for gross misconduct".
The watchdog said both officers' record-keeping was "deficient".
Haroon Jahan, Shazad Ali and Abdul Musavir were killed when they were hit by a car in Winson Green during the riots in Birmingham.
It emerged during the trial that defence barristers were never told of an offer made by police of immunity from prosecution for witnesses involved in the disorder until the 10th week of court proceedings.
The IPCC said the Crown Prosecution Service had since concluded there was "insufficient evidence to provide a realistic prospect of proving that either police officer had knowingly made a false statement and as a result committed the offence of perjury".
Eight men were acquitted of the murders in July 2012.
The father of one of the three men killed in the Birmingham riots says he feels let down by the justice system ahead of the publication of a report into the botched investigation into their deaths.
Tariq Jahan, who was widely praised after he calmed tensions in the city during the 2011 clashes, says he feels like he has had a "slap in the face" after the leaked findings blamed the investigation's failures at the hands of a retired junior officer.
Haroon Jahan and brothers Shazad Ali and Abdul Musavir, all from the Winson Green area of Birmingham, died after being hit by a Mazda car as they tried to protect local shops from looters.
In July 2012, eight men were acquitted of their murders.
Mr Jahan told Channel 4 News: "I'd just lost my son and the police were using me to quell the riots. I expected to get justice and all I got was a slap in the face from the justice system.
"Where were all the senior officers, why were there no notes made, why are bits and pieces of information missing?"