The opening sequence of River (BBC One, Tuesday) reels me in. A woman and a giant of a man are in a car; she's eating junk food and singing along to Tina Charles's I Love to Love. She is Det Sgt Jackie "Stevie" Stevenson (Nicola Walker); he's grumpy Det Sgt John River (Stellan Skarsgård). They share a comfortable familiarity: she teases him and he pretends to hate it, but you can see he loves it really.

The cheesy disco tune is still in my head during the chase that follows, which results in the death of a suspect. So far, so standard police procedural – right up to when Stevie arrives at the scene and the camera pulls away to reveal a bullet hole in the back of her head. She’s dead. River sees dead people. And that funny scene in the car with the bad karaoke now seems sad and full of his grief.

It could be just post-traumatic stress disorder – Stevie was killed in front of him – but it’s not; River sees loads of dead people, or “manifests”, as he calls them. But it takes a while in this richly atmospheric drama for that to reveal itself fully.

When River gets home you think the teenager in his (low-key, Scandi-stylish) flat is his daughter. Then it's slowly revealed that she's dead as well. It's a case he's working on, and he solves it single-handedly. And there's another manifest, who I assume will stay with River throughout the series: Eddie Marsan as a Victorian serial killer.

The drama's writer, Abi Morgan (Suffragette, The Hours), is skilful at unfolding storylines and creating nuanced, memorable characters. As a detective, John River is a stand-out creation, a new take on an often hackneyed genre.

I had wondered if importing the Swedish actor was a lazy way of injecting some Nordic crime magic into a BBC drama, but it’s inspired casting. Skarsgård’s River is sullen, mostly monosyllabic – the scenes where he attends the psychotherapist are terrific – and the star has a powerful screen presence. And Walker is strong and likable, a gobby contrast.

It's disconcerting to see Walker pop up as another detective, in Unforgotten (UTV, Thursday), a more conventional police procedural. It is watchable, although not much in it stands up to scrutiny, least of all the central premise of an entire force marshalled to solve an obscure cold case from the 1970s. The cast, including Bernard Hill, Trevor Eve, Tom Courtney and Hannah Gordon, is top quality.

I haven't mentioned the six-part Unforgotten before because any time I refer to a new UTV drama my email inbox fills up with confused viewers wondering why UTV Ireland isn't showing it. (This week it instead screened Midwinter of the Spirit, seen weeks ago by UTV viewers.)

In Death of a Son: The Killing of Michael Dwyer (RTÉ One Monday) Tom Hennigan, who reports on South America for The Irish Times, describes the killing of the Tipperary man Michael Dwyer in Bolivia as "the most complex story I've ever covered". By the end of this documentary the complexity is clear, the events troubling.

In 2009, 24-year-old Dwyer, described by a friend as “full of go and adventure, out for a good life”, was killed by a secret police unit in Santa Cruz. Two other men with him were killed and two arrested in the same raid on a downtown hotel. Immediately afterwards the police issued a statement saying the men were a terrorist cell plotting to kill the Bolivian president Evo Morales. Buying into that narrative, some Irish media outlets immediately branded Dwyer a “mercenary” and “an Irish Jackal”, running photographs of him that suggested he was a gun for hire.

The photos we now see were almost laughably misleading. One shows him carrying a rifle, in combats with his “training squad” – except we hear from his Tipperary friends that it was taken at an airsoft range (airsoft is a grown-up paintball, played with pretend rifles) when they were all on a day out.

This film follows Dwyer’s mother, Caroline (and sister, as well, although she’s almost silent throughout), as she travels to Bolivia to look for answers to her son’s death and to call for an international inquiry into what was, clearly, an illegal killing.

A mother’s love aside, rational analysis suggests Dwyer was a naive young man who fell in with the ultimate bad crowd – the definition, as much as we know, of an innocent abroad. But who exactly the other men were, and why and how the young Tipperary man ended up working for them, are not clear.

It’s those large gaps in the story, the unanswered but obvious questions, that make this documentary, powerful as it is in portraying the mother’s grief and strength, an unsatisfactory exploration of a deeply mysterious event.

Maia Dunphy's Truth About Breaking London (RTÉ2, Tuesday) seems more like a vehicle for the presenter than a real attempt to explore how she is going to establish a career in London, but what it does do – and does refreshingly – is present a different type of emigrant from the (justifiably) angry economic exiles that usually show up on TV.

Dunphy meets Irish "lifestyle semigrants", young people in glamorous, mostly media careers who moved to London and are doing very well, thank you, while still keeping an eye on the auld sod. She wraps up the lively film with an interview with Graham Linehan, the Father Ted writer.

“In the UK the football coverage is completely staid and boring and the rest of the TV is quite lively and alert,” Linehan says. “It’s the opposite in Ireland. The football coverage is incredible” – cue a clip of Eamon Dunphy in full flow – “and the rest is completely inert.”

Linehan speaks like a man for whom "How rubbish is Irish TV?" is his Mastermind specialist subject. "The best example of that is The Late Late Show. No offence to Ryan Tubridy" – really? – "but, my God, it's extraordinary how archaic and stuck in the 1950s that programme is. It's like no time has passed."

Dunphy snarks about the all-evening duration. “I’d make it a half-hour show. Then it would be good,” says Linehan, who might be right about that.

tvreview@irishtimes.com