The Schoolgirl Terrorist? contains its answer within its very question. Titles are designed to catch your attention. Normally they contain the baldest, most extreme possible summary suggestion of what you are about to see that the makers think they can get away with. A question mark introduces the idea of interrogation, of nuance, of doubt from the off – all things commissioners believe will put people off.

The exception is when the subject is so clearly an abominable, Kafkaesque tale of mismanagement and incompetence visited upon ordinary people. To pretend otherwise even for a titular moment would be to undermine your programme’s integrity from the start.

So, then to The Schoolgirl Terrorist? and the story of Rhianan Rudd, who in 2020 became the youngest girl ever charged with terror offences in the UK. She was 15. She was 16 when she died by suicide at a Nottinghamshire children’s home.

Rhianan’s mother Emily and her older brother Brandon recall a child who always had “a very big whiplash in personalities” and whose mental health seems to have caused her mother concerns from the earliest days. At three she would often insist she was not Rhianan and later invent alternative characters – often “solemn, critical” – in a way that seems to have gone beyond the normal practice of imaginative children. “I was always called a neurotic mother … How can you say that when you don’t live with her?” Emily says she had undiagnosed autism. Brandon says he does not remember a time in the family’s life when social services were not involved and that, by the time his sister was 11, she seemed “depressed a lot of the time, if I’m honest”.

To this mix was soon added Emily’s new boyfriend, an American called Dax Mallaburn, an ex-member of a right-wing gang who said he was trying to be a better man and who was approved by social services to live with them in their post-refuge home. Then came the pandemic and lockdown, and a computer in Rhianan’s own room for the first time. Online, unbeknown to Emily, she met a neo-fascist called Chris Cook. Not understanding why her daughter suddenly began spouting hateful rhetoric of various kinds to family and friends, and after Rhianan told her she had downloaded a bomb-making manual, Emily referred her to the deradicalisation programme Prevent. Soon after that, Rhianan was arrested. Her Prevent case was closed while she was investigated by MI5, as is protocol at such a time. This is perhaps the most striking of the many assaults on common sense already accrued – and that will continue to line the path to tragedy.

She should, after the investigation began, have been referred by either the police or social services to the Home Office unit that deals with modern slavery and trafficking, and exploitative practices like online grooming and radicalisation. Instead, this was only done at the insistence of her defence team long after she had been charged with six counts of terrorism. By then she had also been remanded to custody in a children’s home which seemed ill-equipped to deal with the problems she had, and where Rhianan was able to self-harm despite her mother warning the staff of her history of doing so.

The charges against the 15-year-old were dropped in 2021 when the Home Office made a formal finding that Rhianan had been a victim of exploitation. The inquest into her death would also note the influence of Mallaburn (who Emily had split from by this point), of which her mother was unaware. Therapy via Prevent began. When it started to focus on the “darker” aspects of Cook’s manipulation of her, which involved sexual content, Rhianan took her own life.

By the end of the hour you feel like you have sat through a nightmare, watching Emily and others who loved Rhianan shout into voids that were supposedly filled with people trained and ready to help those in exactly their situation. Instead, it is a catalogue of missed opportunities, failures and – almost the most frustrating, maddening, galling thing – the simple sense that there was no one, or certainly no one high enough up the food chain to make a difference – who had the wit or courage to look at the situation in the round early on and say: this child is not what we mean by terrorist. We have gone badly wrong and we must fix this.

The programme ends, as these programmes always do, with the rights of reply from the other parties involved. MI5 and Prevent point to findings by the coroner’s court that absolve them of blame. The children’s home stands by its care plan and treatment of Rhianan.

“How does anyone know that anything has moved on … I want to know what you’ve done to change what you did with Rhianan,” says Emily. Prevent says her daughter’s death “has informed multiple strategies in our approach to young people and mental health.” I’d say we need more question marks.