When he pulled over to speak with them they walked away and he called for back-up.
Two officers in another car arrived and the trio headed down Roberts Rd in pursuit of the men.
The person wanted in connection with the alleged shoplifting approached police and allowed himself to be handcuffed.
But what appeared to be a straightforward arrest changed when police heard a thud on a nearby lawn.
Thinking it was a bottle, officers quizzed Peeni on what he had dropped, until he picked up the object concealed in a sock.
"I'm going to kill you. It's a f***ing firearm. I've got a gun, I've got a gun. F*** off. Get back, get back," he told them, pointing it at the officers.
A frantic scramble ensued during which the three constables retreated behind their vehicles.
One began to reach for something in the lock box in his car but Peeni dashed over and opened the back passenger door, pointing the sawn-off shotgun in the officer's face.
"You appeared aggressive and agitated," Judge Simon Maude said. "The officers thought you appeared capable of doing what you threatened."
Peeni got into the front seat of the police car, shouting at the fleeing officers to give him the keys.
He released the handbrake and put it in drive, which only saw the vehicle roll into the police car in front.
Peeni followed officers back to Te Atatu Rd on foot but eventually gave up the chase, threw his weapon on the ground and yelled: "I give up, it's not real".
He lay on the ground until officers cuffed him.
While Peeni provided handwritten apology letters to the officers involved, probation were skeptical about his remorse.
The court heard how the 24-year-old had a significant list of previous convictions that featured weapons charges and offences against police.
"This was offending of a very serious kind and I'm sure you won't disagree with me about that," Judge Maude said.
"It appears quite fortunate no one was shot. You were out of control and brandished a loaded firearm ready to fire, not to mention you were using methamphetamine."
Despite his lawyer explaining he had no means of paying for the damage to the police cars, the judge ordered reparation of $1722 on top of the jail term.
NZME rk