The family of a teenage murder victim found a Channel 4 documentary about his case “emotionally draining” to watch, its director said.

Three-part series The Murder Detectives follows the twists and turns of a police investigation into the stabbing of 19-year-old Nicholas Robinson in Bristol last year.

Nicholas Robinson's father Carlos
Nicholas Robinson’s father Carlos (Channel 4)

Unlike previous crime documentaries, it is shot as a drama and follows events in real time, featuring police and detectives from Avon and Somerset as well as Mr Robinson’s family.

Series director Dave Nath said the team behind the films were “immensely grateful” to the family for allowing them access – and added that it was important to him to show them the finished programmes.

“If I’m filming with particularly vulnerable contributors but also just contributors who feature very strongly in films, I always say that I’ll show you the films at the end,” he said.

“Because I think if you don’t, why don’t you feel comfortable showing them? That would worry me.

“So they’ve all seen the films separately, all three films and obviously the police have watched them as well.

“So I think you absolutely have to do that.”

Nicholas and his father Carlos Robinson
Nicholas and his father Carlos Robinson (Channel 4)

Asked how the family responded to the series, he said they found it “emotionally draining”, adding: “But I think they feel it’s important that this kind of subject, why young kids are senselessly murdering each other… and let’s not forget there’s one kid dead here and there’s another kid who, without wanting to pre-empt what happens in this film, his life is destroyed as well.

“And I think they recognise that … we need to do something about it.

“I don’t know what the answer is, but it needs to be talked about and we need to get a handle on it somehow.”

Nicholas's mum, Angela Robinson
Nicholas’s mum, Angela Robinson (Channel 4)

Asked about how the programme’s style differs from typical crime documentaries, Nath said: “I just think we can’t keep on making films the same way.”

He said documentaries had to “reinvent” themselves, adding that he would like to think teenagers of 16 and 17 would watch it.

“We have to start making films in a way that’s going to appeal to them,” he said.

Pc Ifor Williams
Pc Ifor Williams (Channel 4)

Nath also talked about the importance of community policing, and referred to Constable Ifor Williams who appears in the series.

“As the general public, I’m reassured when I see a beat officer on the street,” he said.

“I hardly ever see one to be frank in London, but when I see one I like it.

Luchiano Barnes was arrested for Nicholas Robinson's murder
Luchiano Barnes was arrested for Nicholas Robinson’s murder (Channel 4)

“But following Ifor around in St Paul’s you just realise that he is the eyes and ears of that whole community.

“Not just about investigating a murder, but his presence will reassure some people, his presence will worry some other people.”

Asked if he was worried about repercussions or a backlash in the area from appearing in the series, Constable Williams said he could not be “blase” about his safety in the area, but that there were far more people who liked him than disliked him.

The Murder Detectives is on Channel 4 next Monday, Tuesday and Wednesday at 9pm.