There was a similar case in West Yorkshire in 1975. Stefan Kisko was arrested and convicted for the abduction and murder of an 11-year-old girl, Lesley Molseed. He confessed and served 16 years in prison, until developments in forensic science showed that it couldn’t possibly be him.

In 1992, when he was 40, he was freed on appeal and died a year later of a heart attack. There had been a long campaign by family suggesting he was innocent.

The three senior officers and a forensic man were charged with suppressing evidence but this was never pursued because the lead detective died. The suggestion was that the detectives had bullied a confession out of him.

Even when Kisko was released the detectives insisted he must have been there, and he must have had an accomplice.

These days admissions alone would not be sufficient to convict anyone of a crime. There is a need for other irrefutable evidence, such as DNA or fingerprints.

Both Brendan and Steven have very low IQs. How is a suspect’s IQ considered in questioning?