Procedure, character, or both
Crime drama on British television has always pulled in two directions at once: procedure — how a case is actually investigated, what a police station or squad room is like day to day — and character, the detective or officer whose temperament shapes how you experience the investigation. The best-known series tend to lean hard toward one side or the other.
From the beat to the flying squad
Dixon of Dock Green, following a community police officer in London, set an early tone for the genre: gentle, procedural, more interested in the rhythms of a local beat than in violent crime, and built to reassure as much as to intrigue. Z Cars broke from that tone deliberately, moving policing into patrol cars and depicting officers as flawed, sometimes abrasive, working in a version of urban Britain closer to how contemporary observers actually described it. The Sweeney went further still, following the Flying Squad's pursuit of armed robbery and organised crime with a pace and a moral roughness that had little in common with Dixon of Dock Green's beat officer, and its influence on the tougher British crime drama that followed is considerable. Juliet Bravo, centred on a police station run by a female inspector, kept the procedural focus of the format while shifting its attention toward station management and community relations rather than pursuit and confrontation. Inspector Morse moved the genre toward the puzzle-driven detective story, built around a single investigator working through a case at a deliberately slower pace, more interested in motive and character than in action, and set consistently in and around Oxford, which became as much a part of the series' identity as its lead investigator.
What actually changes across the format
The clearest differences are pace and moral tone. A beat-based procedural like Dixon of Dock Green moves slowly and reassures; a squad-based drama like The Sweeney moves fast and questions its own institution as often as it celebrates it; a puzzle-led detective series like Inspector Morse slows down again, but for different reasons — because the pleasure is in following an investigation's logic rather than its adrenaline. Setting matters too: a series built around a single station tends to focus on procedure and relationships between colleagues, while one built around a squad or a single detective's caseload can range much further.
Choosing where to start
If you want the format at its most reassuring, Dixon of Dock Green shows you where British television crime drama began. If you want to see the genre get harder and more morally complicated, Z Cars and then The Sweeney trace that shift directly. If plot and puzzle interest you more than pace, Inspector Morse rewards patience and attention to detail more than any of the others. Juliet Bravo is worth attention if you're specifically interested in how the format handled station management and a female lead at a time when that was still unusual for the genre.
Finding the archive
As with other strands of classic British television, availability depends on what has been preserved and reissued by a broadcaster or a library service, and earlier series in particular can be harder to find complete than their later, more widely reissued successors. Checking a broadcaster's own archive listing is the most reliable way to confirm what actually survives.