I was lucky to holiday in Burgundy this summer. Every afternoon I ignored the heatwave and pool outside, however. I was watching killers being interviewed on my laptop.

This was homework for the new series of Voice of a Killer Special, on which I am a contributor. This CBS Reality programme takes an intriguing look at how the police interview murderers.

Using real-life interviews, lip-synched by actors, the episodes bring to life the psychologically twisting encounters between detectives and suspects.

Sex offender Colonel Russell Williams

These are nothing like TV cop dramas. They tend to be low-key, very long and sometimes a little dull.

But, if you watch closely, there is always something going on beneath the surface.

The series’ opener is about a particularly chilling and unpleasant killer, Colonel Russell Williams of the Royal Canadian Airforce. He graduated from burglarising homes, stealing female underwear, which he photographed himself wearing, before moving on to rape and murder.

Williams had flown the Queen across Canada

The case is unusual. Williams was not some shady loner. He was the distinguished commander of Trenton, Canada’s largest military airbase. Williams had flown the Queen on her visits to the country.

He was married and high-profile. It is rare indeed for an accomplished public figure to have harboured such a secret, perverted fantasy life.

The most gripping aspect of this documentary is how Detective Jim Smyth cleverly pushes Williams into a corner, until finally he admits everything. Williams thinks he is there to help with police inquiries and subtly reminds Smyth how important he is.

However, Smyth is one of the sharpest minds in Canada’s behavioural sciences unit and slowly reveals incriminating details to Williams. The Colonel finally agrees to indicate where he left one of his victims, Jessica Lloyd.

Expert analysis

Professor David Wilson presents Voice of a Killer Special. Experts analysis comes from forensic psychologists Professor Michael Brookes, Professor Mike Berry, criminal psychologist Dr Donna Youngs and criminologist Dr Samantha Lundrigan.

UK detective Alan Jackaman, an expert in police interview techniques, also gives insights into Smyth’s masterly handling of this serial rapist and killer.

Because Williams confessed in Canada, little is known of the case in the UK. It is disturbing, but also compelling to see the police for once out-thinking the hardest killer to catch – a psychopath.

After watching the expert analysis of Williams on CBS True Crime (starts Tuesday 27 November, 10pm), you could also view the full interrogation on YouTube