Carroll and an associate said they would "rough up Ruckus" and take photos to prove it.
Later, Tucker - who was known to use fake $100 notes known as "Rutherfords" to buy drugs - was introduced to one of the men at a Christchurch house with his nickname of Ruckus.
Unfortunately for Tucker, Boshier said, it was not the same Ruckus who was rumoured to be involved in the armed robbery.
Carroll was told where Tucker was and he is alleged to have arrived at the city house carrying a steering wheel lock.
The Crown says Carroll beat Tucker around the head, causing a skull fracture, as well as a broken nose, broken and missing teeth, a fractured eye socket and broken shoulder blade.
Tucker died from blunt force trauma to his head, the court heard.
It's alleged that Carroll bundled Tucker's body into the back of a car and took him to his friend's house.
They texted the drug dealer and said they had a "prize" for him.
They met at Leeston, south of Christchurch, and set fire to Tucker's body wrapped in carpet and bedding, the Crown says.
His body was found the next day - Anzac Day last year - by Filipino fishermen with hands tied behind his back, it's alleged.
Carroll's DNA links him to the murder, Boshier said.
Justice Nick Davidson told the jury that an earlier trial did not proceed but that they should not think anything into that.
Defence counsel Tim Fournier confirmed Carroll will take the stand in his defence later on in the trial.
"He is going to tell you he had no intention of killing Mr Tucker, and what happened that afternoon got completely out of control," he said.
Carroll accepts he killed Tucker - accepts that he was intending to cause bodily injuries, but didn't know that as a result of those injuries he was likely to die.
A friend of Tucker told how the pair successfully used fake $100 bills to buy drugs.
The counterfeit notes didn't work in shops, the witness said, but had fooled some drug dealers.
The witness, who has name suppression, said they were both using P at the time. He had a $300-$500 daily habit and, at one stage, they'd had as much as $4000 in counterfeit money.
Asked by Boshier if Tucker had any nicknames, he replied: "Yep, he was going by Ruckus."
The trial continues.