Tonight TV: 999 is an intense new series about complex crime cases | television

999: What happened next?

At 10.05pm on Channel 4
In Suffolk, a man stabs and kills a suspected burglar outside his home. In Hertfordshire, a car belonging to a woman reported for drug trafficking was found on fire. Nothing is straightforward either way, as police find in the first episode of this new 999 series. Through footage and interviews with officers and victims, they uncover the details of stalking, lies, and getting back at someone subject to a protection order. Holly Richardson

The Killer in the House: The Murders of Leslie Howell and Trevor Buchanan

9pm on ITV1
More than three decades after the crime that stunned Northern Ireland, this documentary tells the story, including – for the first time – interviews with the children of the Howell family. They were raised by their dentist father, believing their mother had committed suicide. However, the truth is much darker, and it still seems to be emerging. Ellen E. Jones

24 hours in police custody

9pm on Channel 4
We are taken inside the investigation into Carson Grimes, one of the UK’s worst child molesters – who is already serving a life sentence. After a barrage of new accusations, officers begin a new investigation and are inundated with tales of previous victims, as well as the disturbing discovery of bones near his old home. Alexey Duggins

Dark winds

9pm, U&Alibi
In the season finale of the 1970s-set Navajo cop drama, based on Tony Hillerman’s book series, an NTP train station surveillance may finally yield results. But not before Joe (Zane McClarnon) and Gordo (Martinez) get a deep meaning from their hiding place. It’s a brief moment of contemplative calm before events escalate. Eig

Live at Apollo

9.45pm, BBC2
Tom Davis (Murder in Successville, King Gary) is the host on this penultimate night of comedy from the Hammersmith Apollo. It presents rising British Kurdish star Kay Coord and Newcastle actress Louise Young, whose show Feral was shortlisted for the Edinburgh Comedy Awards. Human resources

Things you should have done

10.15pm, BBC 3
Lucia Keskin’s sitcom just got funnier, especially with the addition of Bridget Christie as a devious therapist. Shocked by being called ‘thick’, Chi (Keskin) decides to tick ‘getting a GCSE’ off her life’s to-do list and enrolls at Ramsgate College (well, she storms off to university). Human resources