The family of a man shot dead by police have criticised the four years it has taken for the government to announce an inquiry into why an officer opened fire.

Jermaine Baker was part of a criminal gang trying to spring a prisoner from custody when he was killed by a Metropolitan police marksman in December 2015.

Baker, 28, was sat in the front seat of a car when he was shot once, close to Wood Green crown court in north London. An imitation Uzi was found in the rear footwell, and investigators believe Baker could not have grabbed hold of it to fire at police.

The officer, known as W80, claimed to have acted in self-defence, believing Baker was reaching for a firearm. The officer had been briefed the suspects could be armed and dangerous.

On Wednesday, the home secretary, Priti Patel, announced a formal inquiry into the shooting, to examine the circumstances around it and act as the inquest into the death of Baker, from Tottenham, north London.

The Crown Prosecution Service has already decided the officer should not face criminal charges, following an investigation by the police watchdog, the Independent Office for Police Conduct (IOPC).

In a statement, Baker’s family said: “We welcome the announcement of the public inquiry into Jermaine’s death, and we look now to the inquiry to conduct a full and thorough investigation.

“We are, however, seriously concerned that it has taken more than four years to get to this point. It has been and remains a painful process for our family, and it is long past time that the public learned the shocking truth about how Jermaine died.”

Baker’s mother, Margaret Smith, said: “We can’t talk about what went wrong that day yet but when the public get to know they will be really shocked.”

Although the family welcomed the announcement about the public inquiry, they said they had lost hope in recent years because they had been given five dates first for the inquest and then for the inquiry, which have come and gone.

“We first saw the coroner on 22 December 2015, I can’t believe that more than four years later we’re still waiting,” said Smith. “The key thing we want from the inquiry is the truth, the truth, the truth.”

The family want the inquiry to focus on the planning of the operation that ended in Baker’s death, the amount of force used against him and why things went so wrong.

“Jermaine did not have any weapon. He was unarmed. The only gun that was fired that day belonged to the officer. The other two men who were in the car with Jermaine have been tried, convicted, have served their sentences and are now free to walk the streets again. Jermaine should have been out of prison by now and also walking the streets,” said Smith.

“Everything is on hold for us. The officer who shot Jermaine will continue with his life after this but we have to bear the loss of Jermaine for the rest of our lives.”

Explaining the delay in announcing an inquiry, Sarah Green, of the IOPC, said: “Our investigation into all of the circumstances surrounding Mr Baker’s death was completed within 12 months and a file of evidence was submitted to the CPS in December 2016.

“Its decision to take no further action was made in June 2017. Mr Baker’s family exercised its victim’s right to review and the second decision to take no further action was made by the CPS in March 2018.

“In May 2018, we directed the MPS [Metropolitan police service] to hold a gross misconduct hearing and in November 2018 we received correspondence to indicate the officer would be seeking a judicial review of that decision. Matters have since been before the courts.”

The IOPC believed W80 should face a gross misconduct charge for his decision to open fire.

His lawyers successfully had this decision struck down in court and the IOPC has appealed, with a hearing possibly not taking place until the end of the year.

Announcing the inquiry to be chaired by Clement Goldstone QC, Patel said: “Establishing an inquiry is important to ensure that all of the relevant evidence can be properly considered as part of an effective investigation into Mr Baker’s death.

“HH Clement Goldstone QC is an experienced retired judge who has the expertise necessary to deliver the inquiry.”

The inquiry will need to examine sensitive police intelligence and decision-making by those in charge of the operation.

The shooting led to the arrest of the officer in December 2015 by the police watchdog.

Baker was part of a group of men who were trying to help Izzet Eren escape from a prison van as he travelled to Wood Green crown court from Wormwood Scrubs prison to be sentenced.

The car Baker was in had been bugged by police, and shortly before 9am armed officers surrounded the vehicle and he was shot. Baker was pronounced dead at the scene.

