A multi-award winning programme in Brazil, Merciless is arriving on Channel 4 care of the Walter Presents label on Sunday 18 June at 10:15pm. After the airing of episode one, you’ll be able to stream all 13 one-hour shows as a box set on All4/Walter Presents.

Dark, gritty and stylish, Merciless introduces us to Eduardo Borges, and his first action in episode one – hobbling on fake crutches – is to lure a woman over to his car by dropping some paperwork. As she loads it into the boot for him, he bashes her over the head, and drives her into a woodland on the outskirts of Rio to rape and murder her. Here’s a trailer:

By day, Borges is a charming and intelligent. In his new job as political advisor to corrupt senator Oto Veiga (Aderbal Freire Filho), he suggests an anti-rape campaign that will bring his team into close contact with the police department. Thus, he inveigles his way into the very room where the murders he is committing are being investigated. It turns out that the woman he has just killed was sleeping with the senator too, and a twisty, close-knit plot doubles up on intrigue and moves quickly.

Borges is played by Brazilian actor, model and producer Bruno Gagliasso who, with a cut physique and steely blue eyes, looks altogether too nice to be a serial killer. In between victims – which come at a rate of one every couple of days – he plays a cat-and-mouse game with the FBI-trained profiler Vera Müller (Luana Piovani) and her boss Alexandre Dias (Marcello Novaes). To augment his smooth veneer, or maybe just to play out a new sick game, he begins a relationship with pretty single mother Rayanne (Débora Falabella). The creepiness dials up as he paints her with make-up like a living doll, in just the same manner he does with his dead victims.

Detectives Vera and Alex disagree on how to catch the killer.

Originally entitled Dupla Identidade (Double Identity) in Brazil, the show has been likened to Dexter and The Fall. There’s a touch of Se7en about the presentation, with a hint of hand-drawn gothic madness to the intro credits. Industrial metal often sets the tone and tempo while Borges goes about his bloody business. Swirling around the murders and the hunt for the killer, there’s more than a hint of drama in the relationship between the senator and his family, and between the two cops Müller and Dias. Plenty of heated exchanges.

British and American viewers who are used to more sultry crime drama like The Bridge or the excellent Hinterland, might find the atmosphere a bit uneven. However, it’s an edgy and sometimes violent programme with intensity that builds on two fronts: will Borges be stopped, and will he kill Rayanne?

The show’s Brazilian title translates as Double Identity. He lures them in, and then…

For more Brazilian crime drama, check out Magnifica 70 which is superb and is also available online via Walter Presents. And, you can read about a journey to the dark heart of Brazil with writer Dan Smith, here.