The father of Joseph Burke-Monerville – who was shot in the head by a masked and hooded gunman three years ago – has begged for help tracking his killer, as police offered a £30,000 reward for help solving the case.

CCTV footage of the moment the 19-year-old was killed – as he sat in a car in Hindrey Road, Lower Clapton, on February 16, 2013, with his twin brother Jonathan and elder brother David – was played at an inquest into his death this week.

The teenager, a member of the Nigerian royal family, lived in Canonbury Square.

Security was ramped up at St Pancras Coroner’s Court and 15 police officers drafted in as one former gang member, granted anonymity under the pseudonym Peter Brooks, gave evidence against the three men who had been due to stand trial for Joseph’s murder last May – who were also called to give evidence.

Shahed Nowaz, 20, Roshane Reid, 22, and Scott Andrews, 28, were acquitted when defence lawyers argued the case was bound to fail because it relied on the evidence of just one gang member.

Hackney Gazette: Joseph Burke-MonervilleJoseph Burke-Monerville (Image: Archant)

“Mr Brooks” claims Joseph was mistakenly shot in a gangland tit-for-tat dispute after the A-Road gang held the Pembury Boys responsible for shooting one of their members on New Year’s Eve 2012.

He told the inquest how Andrews had ordered the hit, Reid was the gunman, and Nowaz his accomplice.

All three men deny his claims and Nowaz called him a “liar”.

David Bello-Monerville broke down in court as he recounted the moment his brother was “shot in the face” at virtually point-blank range, after he parked up in Clarence Road to return a scratch card to the convenience store, and two figures approached his car.

“The guy talking to me through the window, he had big eyes and was staring into my car,” he said.

“The shooter asked me, “Are you from Pembury?”, and I said “Mate I’m a big man, you can’t ask me those kind of questions”.

“I realised the shooter was indecisive because he didn’t know whether to believe my statement or not.

“The shooter took a step or two away and asked his colleague, “What do you reckon?”

Hackney Gazette: Joseph Burke-MonervilleJoseph Burke-Monerville (Image: Archant)

“His exact words were “F*** it, light them up anyway”.

“He lifted his hand up. I was screaming, “No. No. No. No.”

“On the fourth ‘no’, that’s when the shot went.

“The first shot came right through the glass. It was like a movie with all this slow motion.

Hackney Gazette: Joseph Burke-MonervilleJoseph Burke-Monerville (Image: Archant)

“I saw the light. I saw the glass shattering in front of me in-mid air and I saw my brother raise his hands but he never got to hold his head.

“His head and his shoulders dropped. The only thing holding him up was the seat belt.”

Mr Bello-Monerville continued: “I shouted, “Why did you do that?” and another shot went off.

“He bent down put his whole face in the window frame and pointed the gun at me. He aimed for my chest. He’s already killed my brother - he was not satisfied, even being unsure if I was from Pembury or not.”

He was able to drive away, despite being shot in the arm, and the pair can be seen running off on CCTV.

Mr Bello-Monerville, who has been left with nerve damage in his left arm and a crippled hand, has also been diagnosed with post-traumatic stress disorder.

His father John Burke-Monerville described how they “never imagined” he would lose a second son.

Joseph’s older brother Trevor Monerville was stabbed by five men in 1994 aged 26. No one was ever convicted of his murder either.

“My wife up until this day has been in torment – I have only seen her once since his death,” said Mr Burke-Monerville.

“Things have not been easy because we had or attempted to have a perfect second chance.

“Once is painful enough, but twice to have lost such precious children – young children, children who passed away before you – you cannot believe. We are in torment. We are in pain. We are begging for the truth. We need help. We are crying for help.”

John Burke-Monerville described how his son was a “kind and loving young man”.

The family had sent him and his twin brother Jonathan to Nigeria to study for five years to “get them away from problems”, and they had only returned to London to study forensics at university six months before the shooting.

He said: “We would struggle and send money for school fees. They would take their money to clothe and feed and pay for other children’s school fees. I was mad when they asked me to find more money, but when I realised the kindness, I realised I had two treasures.”

Jonathan told the court how he would never spent a day without his brother.

He said: “Ever since he passed away things changed. Things I used to do don’t motivate me. There were two of us and I had security. Someone to guide me. Someone to say, “Lets do it that way”. I just miss him.

“I always had the mindset if you’re an innocent person nothing will happen to you. The sad thing is if this can happen to my brother it can happen to anyone.”

Investigating officer, Detective Chief Inspector Glen Lloyd, said it was one of the “most challenging cases” he had seen in eight years at the homicide and crime command.

“Usually we have witnesses, forensics, CCTV avenues - but In this case there is no direct evidence to link the suspects.

“We have heard a lot about the A-Road gang - how ruthless they are, how violent they are, and that’s been one of the problems with people coming forward and providing information.

“I’m totally reliant now on witnesses coming forward.”

Coroner Mary Hassell concluded Joseph was “killed unlawfully”.