Cause to Kill

A murder that copies a case from twenty years ago is the kind of puzzle Taggart does well: cold history suddenly warm again. Twenty years is long enough for everyone involved to have moved on, or to have never moved on at all. Burke is handed a killing that mirrors an old investigation, and the obvious question is why anyone would want to repeat a crime that old. The answer, when it comes, is the nasty one. The copycat may not be the point at all. The target may be someone on the investigating team.

That threat gives the episode its tension. With a forensic psychologist, Dr Irene Russell, at his elbow, Burke works the case knowing the killer might be circling his own people. It turns the procedural into something closer to a siege, where every new victim brings the danger nearer to home. The twenty-year-old murder stops being a historical footnote and becomes the engine of the current threat, which is exactly how a cold case should be used.

Glenn Chandler and Martin McCardie wrote it, James Henry directed. Alison Peebles is a quiet asset as Dr Russell, and the regulars do the heavy lifting: Alex Norton's Burke, Blythe Duff's DS Jackie Reid, John Michie's DI Robbie Ross and Colin McCredie's DC Stuart Fraser. Around them circle Phil McKee's Colin McGuigan, Des Hamilton's Brian Paterson, Shabana Akhtar Bakhsh as Layla, Finlay Welsh's Grant Todd and Deborah Arnott as Mary Clark.

The episode earns its unease by keeping the killer close. There is a particular chill in realising that the target may be a colleague, and the writing leans on that without overplaying it. The forensic work stays believable, the suspicion spreads fairly, and the past does the scaring instead of the decorating. It is satisfying television of the patient kind.