But the German Shepherd wasn't paying attention; his eyes glued to the blue ball.
Unlike his partner, Muir is no rookie.
He has been a police officer for 20 years, 14 of those as a dog handler.
He said having a dog as a partner is "way better" than the human alternative.
"Peace and quiet in the car," he added with a laugh.
Parko is Muir's third operational police dog.
He had his first dog for 10 years. Sadly, it died two weeks after retiring.
"He didn't suffer. He had a good working life. He was a pretty sharp police dog."
Muir said each dog has a different personality.
Parko is quite placid at times, which can be a good thing.
"They don't have to be this big snarling mess of aggression ... "
But they should still be able to turn it on when the time comes, Muir said.
That could be when responding to a stolen car, a robbery or any kind of crime where offenders are running.
The dog handlers also get called out to domestic violence incidents.
"We go to those because you don't know what's going to happen there."
Muir said police dogs are also used as a tactical option.
"If there's a violent offender in a house, we'll be called."
There are also public displays and community education sessions at schools and different events.
Muir said there was a big display for the men's and women's New Zealand Sevens teams about a month ago.
"And I heard three or four of them want to join. There are a couple that want to be dog handlers."
It's a rewarding job, but one which requires near-constant training and up-skilling.
"So you just don't get operational then that's it for the rest of your police career, you get tested twice a year and the tests can be quite hard," Muir said.
"You can't let it slide. You want him to develop to be the best police dog he can. Even though he's operational, there's still a lot of potential in him to be a lot better than he is now."
To get to this point, Parko has passed three three-week courses in Wellington.
His obedience, tracking, and bite work all had to be at a certain standard before graduating.
"It's a lot of work. I think only 50 per cent of the dogs that start pass," Muir said.
Parko was sent to Tauranga as an 8-week-old puppy after being kennel bred in Wellington.
He was put into a foster home before Muir took him in at about 7 or 8 months old.
From there Muir trained him and Parko will continue to stay with him at home.
He is a working dog though.
"He doesn't come and sleep by the fire, you know, he still sleeps outside and he's never inside. Never."
And there are no special doggy treats for dinner, just police-issued biscuits.
But it is still a close bond – this partnership between human and dog.
Almost as close as the one between dog and blue ball toy.
