Adrian Bayley was calm and relaxed as Detective Sergeant Paul Rowe began his interview to nail the killer of Melbourne woman Jill Meagher.

Bayley thought he’d gotten away with it, according to Conviction – a documentary with deep access to what happened behind the scenes of the Meagher investigation, shown on Tuesday night on ABC.

Meagher, a 29-year-old Irish woman living in Melbourne, disappeared on September 22, 2012, while walking home along Brunswick’s Sydney Road after a night out with friends.

Her disappearance – and the tragic discovery of her body six days later – captured the attention of Australians everywhere and raised important questions about the safety of women after dark.

The ABC’s film painstakingly recreated the search for Bayley – a man with a shocking history of rape and violence who was out on parole while appealing a sentence for a previous violent offence – the building of evidence and his subsequent arrest.

Under intense public pressure, Det. Sergeant Rowe, who had four years of homicide experience behind him, planned this crucial interview.

He began by establishing a rapport with Bayley, chatting with him about the footy (Bayley supported Collingwood) before then gently leading him through his story of what he’d been up to that evening.

Bayley said he’d been to a bar with his girlfriend, had an argument and had gone home and stayed there – a story police knew was a lie.

Progressively, Det. Sergeant Rowe introduced Bayley to the evidence and watched as his demeanour changed.

When he asked him how he could explain a photo of his car going under a bridge on a motorway, given he had said he didn’t leave his home, Bayley started to crack.

“It’s a definite point in the interview where I could see his attitude, his demeanour and his complexion change. Once he realised that we had information that gave lie to his story, he became rattled, uncomfortable,” Sergeant Rowe recalled.

At that point, another policeman was sent to stand outside the door because they feared Bayley would become violent.

Detective Sergeant Paul Rowe interviewing Adrian Bayley. Photo: ABC

“When I told him that we had found Jill’s sim card at his home address it was a fairly significant moment from an investigative point of view,”Det. Sergeant Rowe said.

“He had said, ‘I can’t explain it, I can’t explain it’, and then when I told him about the sim card he said, ‘I don’t want to explain it’.”

Bayley then said he wanted to “get it off his chest” but it “became all about him”, how he was really “a knight in shining armour”, and “a victim”.

Det. Sergeant Rowe appealed to his compassion to show police where he had taken Jill’s body and, some hours later, Bayley agreed, with Det. Sergeant Rowe “nursing him through it”.

Paul Rowe left the Homicide Squad after solving the case. Photo: ABC

In the car, they kept driving past the same road with Bayley “slumped on the car door, not engaging, not being overly helpful”.

Eventually, according to Det. Sergeant Rowe, he said “yeah this is it, stop here” and started crying.

Det. Sergeant Rowe remembered Bayley being “broken” by the end of the process.

Bayley was sentenced to life in prison for this murder and other crimes. But these cases harm people on all sides.

Police regretted initial suspicion

For example, the investigation’s team leader, homicide detective David Butler, recalled he regretted the initial investigation of Tom Meagher, Jill’s husband, as an early suspect, while noting it needed to happen at the time.

“This poor guy. Not only has he lost his wife, but he’s being treated pretty badly by us. I’m the guy who’s in charge of the investigation. It comes back to me,” Det. Butler said.

Police regret how they treated Tom Meagher in the wake of his wife’s death. Photo: ABC

Det. Butler was moved to tears when he recalled the impact such cases also have on the lives of the police involved.

Two of the forensic squad who went to the site of Jill Meagher’s burial never returned to work. Det. Sergeant Rowe, too, eventually left the homicide squad.

At the end of the film he noted: “I had great pride in that investigation and what we were all able to achieve. But it’s a tragedy and there’s no winners.”

Watch a clip from Conviction below: