Special report: Five years on, gang shatters family’s dream of feud-free life

But on October 17, 2007, Jonathan Matondo was shot through the head in a children’s play park, the victim of what police think was a gang feud.

His case shocked Sheffield, the city in which he and his mother had made their home, and sparked questions for police and politicians nationwide.

To this day, nobody has been convicted of Jonathan’s murder, despite detectives’ efforts, and a culture of silence still hampers their investigation.

Chief Superintendent Martyn Bates, who led the investigation in 2007 and is still in charge of it today, freely admits the gunman is at large. But as South Yorkshire’s head of specialist crime services, in charge of all the force’s major investigations, he also insists the case remains a priority.

A 19-year-old, Negus Nelson, was charged with killing Jonathan and faced trial twice, after the first jury to hear the case failed to reach a verdict.

Mr Bates said: “It was never our case that Negus Nelson acted alone, we were always looking at other people involved, even during the court process.

“Since then, we have conducted extensive work in terms of overtly trying to gather evidence against those people, but also covertly to obtain information.

“We need evidence sufficient for the Crown Prosecution Service to bring further charges. Unfortunately, we’ve not, at this stage, reached that position.”

Mr Bates said he and his officers knew the details and background, but “limited co-operation” from those who could give statements still left them frustrated.

He said he would not go into detail about covert methods, but added people who had been identified as able to give evidence were continually targeted by his team.

“We have continued to monitor people we think were involved, people who, if they chose to, would make good witnesses and give key evidence,” said Mr Bates. “When certain elements have fallen out, or somebody has gone to prison, we visit them and take every opportunity to let them have a prick of conscience.

“If one or two of those people came forward tomorrow, we would have sufficient evidence to charge somebody who would be convicted of murder, I am certain of that.”

Detectives believe the “core” of the gang responsible for Jonathan’s death is made up of just a few people, who have warned others not to speak out.

However, Superintendent Dave Barraclough, who polices gangs, said he believed their influence was now waning, making a conviction more likely in future.

He said: “I think what is crucial is that a lot of mentality has changed within communities. You will always get people who will be in fear of speaking.

“But the vast majority don’t want it on the doorstep, They won’t tolerate it. The younger element have seen deaths, and are not keen for their families to be involved.

“Five years ago there was an undercurrent of activity that was almost seen as ‘well that’s just what kids do around here’. But the deaths have changed that.

“What is acceptable is now distinctly different, but there are still problems, poverty and other issues such as poor education, it is still there.”

Mr Bates said Jonathan Matondo’s mother Therese Mfuilu, who brought her son to Yorkshire from the Democratic Republic of Congo, has now moved away from Sheffield.

“High-profile murders like this are looked at closely and reviewed extremely frequently but the family left the city to move back to wider family in the south,” said Mr Bates.

“They were a very good family in many respects and had left very difficult circumstances back in the Congo.”