Ted Bundy was one of the world's most brutal serial killers, having taken the lives of at least 30 women throughout the 1970s.
Bundy - who was executed in 1989 - preyed on unsuspecting women, luring them into his vehicle before brutally murdering and dismembering them. Experts believe the number of lives he took to be far greater than the 30 he eventually admitted to.
Now, in a new documentary on its way to discovery+, Ted Bundy: A Faking It Special, experts in body language, speech and forensic psychology examine footage from Bundy's jail cell in 1977, highlighting three specific gestures that 'nail' his guilt.
You can watch a clip below:
In one interview - in which Bundy actually invited interviewers into his cell - forensic psychologist Kerry Daynes explained the killer tries to portray himself as being confident and relaxed.
"Bundy is doing everything that he can to project a confident, relaxed persona. It's a full-on charm offensive," she says.
Meanwhile, body language expert Dr Cliff Lansley, believes this is Bundy's attempt at making himself seem 'likeable'.
"So, he's very clever here, and he's trying to move in and engage and create a good impression," he explained.
"If we can help people to like us then they'll trust us and believe us, and if we can create that vulnerability and likeability, it's a powerful influencing tactic."
At the time of the interview, Bundy was awaiting his murder trial, asserting during the chat that he expected to be cleared of the allegations.
But Dr Cliff points out three gestures that contradict Bundy's claims of innocence.
"Number one, we get an eye closure, which distances ourselves from the words we're using. Number two, we get a shoulder shrug from one side, and this is a partial expression - leakage - of the full expression of 'I have no idea what I'm talking about'.
"But to nail this, we get a little head shake 'no.' And when you're saying something affirmative, but your body is leaking something in the negative, you can trust the body. Because most of these body signals are below consciousness."
Dr Cliff explains the ultimate clue comes when Bundy stares down the camera lens.
"Now, Bundy's emotional intelligence, or self-awareness, I judge to be high. What gives me that conclusion is that every time he makes these slips, which are below consciousness, maybe he knows he's not convincing," he explains.
"What gives us a clue is a few seconds further on we get this stare right down the camera lens. I think he knows he's slipped up; this camera check is a semi-conscious check-in of his audience to see if he's getting away with it."
The experts go on to point out the stark contrast to December 1977, when Bundy managed to escape jail, killing four students at Florida State University and 12-year-old Kimberley Leach while on the run.
When he returned to custody, he was filmed as his indictment was read to him - and his behaviour is a stark contrast.
"So here we have Bundy walking into a room where the Sheriff is going to read an indictment of the charges that have been levelled against him. Bundy has no power now, so his ego comes into play and he disrupts the process," says Dr Cliff.
"However, what he's leaking immediately before that assertive, confident attack, is a lot of nervous behaviour where he's manipulating his clothing and his neck. It's likely that he's trying to comfort himself; his heart is probably going at 120 beats a minute here, but he's trying to keep calm.
"What we see here is the lips rolling in, like this, and the brows are coming down, you see a little bit of a ridge forming here. So, the combination of the brows down and the lips rolled in, are a reliable indicator of anger. He's furious as well as anxious about the situation he's in."
Shortly before his execution, Bundy confessed to 30 homicides, but detectives believe the real number to be much higher.
Ted Bundy: A Faking It Special is available to stream exclusively on discovery+ from Saturday 26th June.
Chosen for YouChosen for You
Most Read StoriesMost Read