Last night saw the conclusion of ITV’s three-part true-crime drama adaptation, Des.

David Tennant who took the lead in a “skin-crawling” portrayal of serial killer and necrophile, Dennis Nilsen, was praised for his “outstanding” and “considered” performance but for many viewers, it had a somewhat “underwhelming” resolution.

The drama adaptation didn’t seek to glorify Nilsen’s horrendous crimes and therefore began the story at the point of Nilsen’s arrest.

We saw the Scot immediately confess to his crimes, in a cold, calm and collected manner later going on to reveal that he had killed up to 15 young men in short, vague and nonchalant statements.

We discovered that despite his admissions, Nilsen could only be charged on six counts of murder and three counts of attempted murder putting him behind bars for the rest of his days but Des didn’t really touch on the man before the murders – and that’s where The Real Des comes in.

Airing tonight on ITV, ‘The Real Des’: The Dennis Nilsen Story will delve deeper into the mind of the killer, narrated by Tennant himself.

The hour-long film looks set to address much of what Des didn’t, starting off at the very beginning – exploring elements of Nilsen’s upbringing and the significant events that may have contributed to his inner evil.

The Real Des will scratch beyond the surface and further explore his time spent in both the army in 1961, the Metropolitan Police and then as a civil servant working at a local Jobcentre.

The documentary will also feature new unseen material, including frank interviews with victims’ families and footage from Nilsen’s interview at Albany Prison in ’92, in which he admitted to his crimes in full, with little to no remorse.

Experts will also give their opinions on the case and dissect his inner psyche.

‘The Real Des’: The Dennis Nilsen Story airs tonight on ITV at 9pm.

Images via ITV / Alamy