Killer wanted to 'play God' by setting abduction trap

Mr Griffiths was last seen alive in the Brisbane CBD on January 16, 2022 before his mother reported the 35-year-old missing on Australia Day that year.

Mr Griffiths was taken by car to Coopers Plains, south of Brisbane, and died on January 17, 2022 but police are yet to find his remains.

Crown prosecutor Chris Cook said Bornstein decided to take part in "retaliation" because of allegations a person close to his friend, Filip Grbavac, had been abused by Mr Griffiths.

"Instead of letting the authorities deal with any allegations, Grbavac and Bornstein thought that they would get involved themselves, that they could play God," Mr Cook said.

He said Bornstein set up a late-night drug deal with Bornstein at a Brisbane hotel on January 16, 2022.

Grbavac told Mr Griffiths he had to travel with him and Bornstein to Coopers Plains to be paid for the deal.

Mr Griffiths' last communication was a text message sent at 3.03am the next day that said "Bro, I think I'm being set up" along with a link to his phone's location.

Mr Cook said a witness saw Mr Griffiths being punched at a warehouse and police had obtained a photo of his body wrapped in plastic.

"What occurred was a brutal, and must have been prolonged, attack to kill Mr Griffiths," Mr Cook said.

Mr Cook said Bornstein was not present when Mr Griffiths was killed but he had known Grbavac intended to cause serious physical harm.

Grbavac, described as the "prime offender" by Mr Cook, died of critical head injuries after an alleged fight with another prisoner in February 2024.

Mr Griffiths' mother read from her victim impact statement and said she regularly woke at 3.03am with horrendous nightmares.

"You have imprisoned us to a life of waiting, of stomach-churning heartache every time we hear of someone's remains being found. Is it Lachie? Do we finally get to put him to rest?" she said.

Earlier in the sentencing, Bornstein said he "never meant to hurt anyone".

"I've spent a lot of nights awake wondering what Mr Griffiths' family might be feeling ... if I had known what was going to happen that night, I would never have gone to Lachlan," he said.

Defence barrister Michael Bonasia said Bornstein had been a heavy drug user at the time.

"This offending can be described as misguided loyalty to a friend ... his statement earlier was one of genuine remorse," Mr Bonasia said.

Justice Frances Williams reserved her decision on sentencing to a date to be set.

David Lee Tan, 42, last week also pleaded guilty to the manslaughter of Mr Griffiths and is due to be sentenced on Thursday.