The Prosecutors: Real Crime and Punishment, BBC Four

Murder is entertainment, which is why crime and the legal process are on television every night. But where drama and documentary focus on criminals and the police who catch them – and the barristers who cross-examine them in court – vanishingly little attention is paid to the worker bees of the legal process. That's partly because the Crown Prosecution Service is a shy organisation.

Each episode has focused on contrasting cases to illustrate the many different ways in which evidence is evaluated and presented to best effect in court. In the first, a motoring collision between two cars caused the death of a schoolboy and the CPS had the laborious process of working out which charge was most likely to secure a conviction. It also followed the successful prosecution of a gang of burglars who blew their way into banks by targeting cash machines. The second programme moved onto murder: one man had killed his elderly mother, and another had fatally stabbed an old flame he’d met again online. The final programme visited two historic crimes: a murder that had gone unsolved since 1993, and the prosecution of a schoolmaster who abused a large number of pupils in the 1970s and '80s.

The series did not attempt to do anything as vulgar as make the pulse race

The presence of DPP Alison Saunders in two of the programmes suggests that this was seen by the CPS as a way of garnering positive publicity (much needed, in her case, after the stick she took for not prosecuting Lord Janner). It certainly felt like an extremely well-behaved outfit, its employees coming across as diligent, conscientious and thoughtful. This impression was enhanced on the many occasions where conversations featured prosecutors telling each other things they already knew for the benefit of the viewer.

A bit like doctors, they had to leaven the horrors of the job with humour. Some of these horrors appeared on screen: a pool of recently spilled blood; CCTV footage of a murderer leaving the scene; a man calling the emergency services as his neighbour died in front of him. Interwoven with these were overhead drone shots of the Mersey (most of the series was in Liverpool and Chester), which subtly reminded the viewer that prosecutors must detach themselves from emotions which might cloud their judgement.

The one question that was never quite answered was why it can take so long for cases to come to court, but three explanatory hours immersed in the world of the CPS supplied a thorough grounding in the intricacies of prosecution. The series did not attempt to do anything as vulgar as make the pulse race, running the risk of seeming rather dry. Prosecutors never meet the accused, so nor did the viewer, apart from in footage from police stations. In lieu of images from the courtroom, cross-examination transcripts scrolled silently across the screen. An eminent QC explained how he attempts through oratorical tricks to sway the jury, but wasn’t heard in the actual act.

And yet every programme delivered a powerful finale. In the first episode, it was the mother who found it in her heart to forgive the man who accidentally killed her son; in this last it was the cathartic conviction – after more than 21 years, the death of her parents, and a crucial change in the law – of Claire Tiltman’s killer (pictured above, the school friends who campaigned for her case to be reopened after her parents' deaths). Jointly produced and directed by Sara Hardy and Blue Ryan, The Prosecutors has been the most enlightening insight into the sober and stolid certainties of the British legal process since 24 Hours in Police Custody.