At about 9.30pm on December 8 last year, Heappey got a text at his Bishopdale home from heavily-tattooed patched Nomads gang member Sim asking where he lived.
Heappey told 51-year-old Sim – who earlier pleaded guilty at the High Court in Christchurch to a charge of causing grievous bodily harm with intent to injure - who headed around.
Sim then drove him to his Russley house, the summary of facts says, and then texted others in the gang.
"Got Smiley," Sim texted. A response told him to keep him there.
At about 10.50pm, two gang affiliates showed up, driven by a third person.
Heappey went outside where a fight broke out.
He was stabbed in the chest and arms and punched when he fell over, the court heard.
"Due to the injuries sustained by the victim he lost any ability to defend himself or physically respond to the attack," says the summary of facts.
After the attack, Heappey was bundled into a car by his assailants and driven to Christchurch Hospital.
Hospital staff took the bleeding Heappey out of the back seat before the driver took off, crashing into a parked car.
Although hospital staff tried to save his life, Heappey died from his injuries at the hospital.
He was stabbed and cut 14 times during the assault, with defensive injuries to his left arm and hand, one stab wound through his forearm, three stab wounds to his chest, and two penetrating his heart.
Later, Sim acknowledged to police officers that he had driven Heappey to his house.
But he denied that either Heappey or any other person was on his property at the time the fatal assault took place.
"Sim further stated that as much as he wanted to tell police what happened to the victim, he could not," the police summary of facts said.
This afternoon, Heappey's family told of their lives being torn apart by the murder of a son, brother, father, and friend.
A spokeswoman said they believe Sim and Heappey were mates and had been in regular contact in the weeks leading up to his death.
Sim was "directly involved" in taking his life, the family say, and even though he may not be facing a murder charge, it doesn't make him any less guilty.
Defence counsel Lee Lee Heah says that Sim understands that, in the eyes of the victims, he is as equally culpable as anyone else.
"He is truly, truly sorry and, if he could, he would undo his part in this incident," she said.
"He understands the pain that the family has gone through and will go through for a long, long time."
Heah said that Sim is now ready to change his lifestyle and to finally leave the gang.
Justice Rachel Dunningham told Sim, who has more than 100 criminal convictions, that he is assessed as being at a very high risk of reoffending, which won't reduce until he distances himself from the Nomad gang.
She jailed Sim for two years, three months.
Four other people have been charged over Heappey's death, including two men charged with his murder who are due to stand trial next March.