Cold case: How police caught up with killer of Bowen man Rex Keen

A Queensland killer walked out of a hotel room almost 50 years ago hoping what was inside would never catch up with him, but he left something behind that would uncover his dark secret.

A Queensland killer walked out of a hotel room 47 years ago hoping what was inside would never catch up with him, but he left something behind which would uncover his dark secret.

Behind that door lay Rex Kable Keen, 46, bashed over the head with a camera and left to die in Lennons Hotel on Queen St in 1976.

It was dubbed the Black Friday Murder, unable to be solved until police cracked the case back open in 2019.

Queensland Police Homicide detectives have now opened up about how they solved the cold case and how one man’s decision years earlier unknowingly ensured the killer’s demise.

Rex Keen was a young hotel manager from Bowen in North Queensland, funny and a classic Aussie bloke.

He was visiting Brisbane for some medical appointments and decided to head out for some drinks while in the city on an August night in 1976.

Rex Kable Keen was a hotel manager in Bowen. Supplied.

Rex Keen died when he was 46 years old.

He met a man, Benjamin Jansen, and the pair went back to Lennons Hotel bar where Rex was staying on Queen St. They went up to his room and ordered room service.

A waitress delivering their food was the last person to see him alive besides his killer.

Inside the room, Jansen told police Rex made an unwanted sexual advance at him, approaching him with a camera and asking to take his photo.

Jansen grabbed the camera and bashed Rex over the head, leaving him to die on the bed.

He laid there suffering, bleeding and alone, for up to eight hours before he finally took his last breath.

Rex Keen was found dead at the Lennons Hotel in Brisbane.

. Police looking through rubbish during the investigation into the death of Rex Keen.

Police issued a reward for information at the time of Rex’s death.

Jansen fled with the camera he used to kill Rex, but he left behind a tissue – the crucial piece of DNA evidence which would lead police to his door 43 years later.

Homicide Investigation Unit Detective Senior Constable Adrian Stanborough was one of the officers to knock on his door.

He picked up the cold case in 2018 and began a review of all material from the original investigation including witness statements, crime scene photos, and forensic evidence.

Among the evidence was a box of exhibits from the crime scene, including a used tissue.

“The exhibit was found in the middle of blood. So there was blood in the crime scene and the tissue was found with no blood on it, like it had been dropped on top or something,” he said.

“We don’t know if that tissue may have been in his pocket, or fallen out of his pocket, or whether he used the tissue in the room and left the tissue.”

A newspaper clipping from 1976 showing confits of a suspect witnesses had identified.

The evidence was tested for DNA and returned a result – a man who had committed fraud in 2003 in a completely unrelated case.

It was Benjamin Jansen.

Detective Stanborough said the police officer’s decision to take Jansen’s DNA in 2003 changed everything.

“Had that DNA not been taken this would probably still be unsolved,” he said.

“Ben Jansen’s name had never come up in the original investigation.”

Police then planned their tactics and Detective Stanborough approached Jansen at his Bundaberg home in 2019.

Benjamin Jansen was harbouring a dark, decades old secret.

“It was almost like, I can only describe as it was like the weight of the world was lifted off his shoulders when he saw us. I just remember the look on his face,” he said.

“He lived with this at that point for I think it was 43 years and never told anyone, and all of a sudden we rock up to his doorstep, start asking him some questions about it, and then I just knew I knew straight away, like he almost started crying. And I could tell … this is the guy.”

Just weeks later he was arrested, but denied everything.

Detectives arrest Jansen over the death of Rex in 2019.

“We basically put all the allegations to him. He denied it,” Detective Stanborough said.

“And then, we had actually finished the first interview … and he made a comment about how the family wouldn’t want to know what happened.

“We started a second interview, and that’s when he made full admissions.”

Jansen, 73, was charged with murder, but he pleaded guilty to manslaughter in October last year.

He was sentenced to nine years’ jail and released on immediate parole after 1205 days already served in custody since his arrest.

Detective Stanborough said he was glad to bring Rex and his family closure.

“Homicides in general are hard, they affect so many people, and it’s nice just to be able to give a little bit of closure to families.

“It doesn’t make it any easier for them, but to give them some answers about what happened to their loved one (is important).”

The family of Rex Kable Keen pictured leaving the Supreme Court with cold case detectives during the sentencing of Jansen. (Image/Josh Woning)

“I was really proud to be involved in the investigation and such an old investigation.

“There’s not too many police who could go through their career and say they were involved in solving a 43 year old murder.”