As darkness falls on Midland train station, police dog Gypsy is in no mood for games.
The four-year-old German shepherd is eyeballing every person who dares walk within a 10m radius.
Her already-gigantic ears appear to double in size and swivel at the slightest noise.
She is silent but one wrong move from an overzealous punter will see her morph into a snarling ball of teeth and saliva, a weapon of intimidation akin to anything her handler, Sen. Const. Grant Bears, keeps on his police belt.
It's a far howl from an hour ago when Gypsy could easily have been mistaken for just another family dog in any other WA backyard.
Chasing an old toy across the grass, her tail wags furiously as she doles out sloppy kisses to Sen. Const. Bears' cheeky five-year-old son Dayne.
"People come over and wonder how she can be a police dog," Sen. Const. Bears said. "If I walked her down the street you would just think she is a beautiful pet. Not many people see the other side to her."
Snarling beast: Officer Grant Bears with police dog Gypsy. Picture: Michael Wilson/The West Australian
The change in Gypsy's demeanour is palpable as soon as Sen. Const. Bears yanks open his garage roller-door to begin his nine-hour shift.
"She hears the roller-door go up, I come out with my uniform on and she starts barking," he said. "Once the collar goes on she knows she's going to work."
At 28kg, Gypsy is the smallest of the general purpose dogs in the ever-growing WA Police canine unit.
Officer Grant Bears with police dog Gypsy. Picture: Michael Wilson/The West Australian
She has been Sen. Const. Bears' partner and family pet for three years. In that time Gypsy has tracked down more than 100 offenders or their discarded property.
Recently she traced a scent for 2.5km despite the suspect having a 15-minute start.
Even Sen. Const. Bears had given up by the time Gypsy led him down a dark Bayswater street to find the wanted man wielding a samurai sword.
"He still had the sword with him and decided to be silly so she decided to teach him a lesson," Sen. Const. Bears said.
The dogs are taught to follow the freshest human scent, which includes people's odour, clothing or even particles of skin left behind.
Where an airborne scent is faint, the dogs track the smell of disturbed grass or dirt.
If a person surrenders, the dogs are trained to stop and bark until officers arrive. But they will attack if they perceive a threat.
"None of us wants the dogs to bite," Sen. Const. Bears said.
"They are there to protect us when we need it, like a taser or firearm."
On the beat: Officer Grant Bears and Gypsy at Midland Train Station. Picture: Michael Wilson/The West Australian
Compared with standard paddy wagons, dog squad vehicles have unique modifications, including an emergency trigger so the dog can be released if their handler is in trouble. "She knows if that hatch opens, dad needs help badly," Sen. Const. Bears said.
The dogs are trained not to look for food while on duty and a tug toy, not a snack, is used as a reward.
"If an offender throws a lamb chop at her, it's just going to hit her and she'll keep going," Sen. Const. Bears said.
Since its creation in 1993, the WA Police canine squad has grown from two dogs to almost 40, including the narcotic and bomb detection dogs.
Acting Sen. Sgt George Bogunovich said the fear factor when the general purpose dogs were deployed was an invaluable weapon and most suspects gave up without a whimper.
At "a dollar a day to feed", he said the dogs were extremely cost-effective at a time when government agencies were tightening their belts.
Police statistics show dog squad arrests and arrest assists have jumped 18 and 24 per cent respectively over the past three years.
"Despite all the advances in technology over the last 20 years, dogs are as important to policing as ever," Acting Sen. Sgt Bogunovich said.