As she waited for Edmonton police to arrive, Deanne Elliott prepared to go to jail. She told an employee to hide their vehicle so it would not be impounded and she removed wheel immobilization boots from all but one of the vehicles her company RFM Parking had "booted" in the parking lot in order to cut her losses if they got confiscated.

Then as an extra measure, she even removed the blouse she was wearing under her heavy jacket emblazoned with the words Parking Enforcement.

The Denver Boot prevents drivers from moving their vehicles until they pay a fine to get it released. Police in Edmonton say it is against the law. (Terry Reith/CBC News) She explained that the last time she was in jail, it was extremely cold and she was only allowed to wear one layer of clothes. This time she wanted the extra insulation.

RFM Parking has been playing a cat and mouse game with police agencies in the Edmonton region for more than a year over the use of the so-called Denver Boot as a tool of parking enforcement.

The company patrols private parking lots, putting Denver Boots, which prevent a car from being driven away, on vehicles parked without authorization. There are no tickets or advance warnings, and RFM will not remove the boot until a $300 fine is paid.

But Edmonton says the practice is against the law and has twice arrested Elliott's business partner Derrick Cantwell.

1st arrest in November 2015

RFM's brushes with the law began in November 2015, about one year after it expanded to Edmonton. The company was contracted to patrol a parking lot across the street from a busy university campus.

Derrick Cantwell, co-owner of RFM Parking, is facing charges of mischief and extortion over his use of the Denver boot to immobilize vehicles parked without authorization. (Sam Martin/CBC News) "You can imagine every student in Grant MacEwan thought that this was free parking," Cantwell says of the situation he saw in the lot, which serves several businesses.

But when he began putting Denver Boots on vehicles left by people crossing the street to campus, police were called.

"They came right over, they said, 'You're under arrest,' they threw on handcuffs and shackles."

He says he and an employee spent the next 36 hours in an Edmonton police cell.

They were charged with fraud, mischief and extortion. All of the charges were later dropped.

The last time Elliott was arrested was four months ago, and she spent 18 hours in an RCMP jail cell in the Edmonton suburb of Sherwood Park.

"It was horrendous. I've never been in handcuffs, never been in jail, never had anything more than a speeding ticket," she recalled. "Law-abiding citizen who pays taxes ... and yes, I was thrown in jail."

The controversial Denver Boot

People attending a funeral in Moncton, NB were outraged to find vehicles parked in a lot across from the church had been booted. The company that applied the devices, Parking Solutions, defended its actions saying they were not authorized to park there. (Jeff Burns/Facebook) The Denver Boot was invented and first used in the Colorado city that it's named for in 1955. Many municipalities quickly discovered that it is a far more efficient method of cracking down on illegally parked cars than the standard practice of issuing tickets and towing vehicles to impound lots.

"It's an aggressive way to get someone's attention, but in some cases it's the most economical and easiest way to encourage some compliance," explains Carole Whitehorne, executive director of the Canadian Parking Association.

Use of the Denver Boot by private companies such as RFM is growing as they expand in Canada.

Cantwell, who opened his first parking operation in Fredericton 11 years ago, says he wants to establish RFM as a national entity. It currently does business in Atlantic Canada, Alberta and British Columbia.

He's had brushes with police in the past, but always managed to convince local authorities that what he is doing is legal. But after more than a year, two trips to jail, and three rounds of criminal charges he has yet to convince police in Edmonton that his method of parking enforcement is not criminal.

In a written statement, EPS Detective John McConnell states that use of the boot is a criminal act. "There's the act of mischief to another person's vehicle by rendering it inoperable. A second criminal charge of extortion may be appropriate when the vehicle owner is approached in the lot and forced to pay a fee before the device is removed."

Is it a crime?

RFM Parking says by posting signs in the lots it patrols, it obligates those using the spaces to follow the rules, or risk having a boot placed on their car. (Terry Reith/CBC News) The Denver Boot has been used in Canada for decades, mainly by municipalities and universities to crack down on drivers who amass unpaid parking tickets. It's used in Montreal and Saskatoon, where only bylaw officers and bailiffs are allowed to clamp it on.

Cantwell maintains what he is doing is legal because the lots RFM patrol are private property and anyone who parks in them is entering into a legal contract to abide by the rules. Those rules are spelled out on signs both at the entrance, and within parking lots.

"If there's a sign in a parking lot, it's your job to read the sign," he explains. "You get out of your car and read the sign. You make your decision whether or not you belong there. If it turns out you get booted because you read the sign and decided to ignore it — it's your own fault."

In Edmonton, RFM is charging drivers $300 plus tax to have the device taken off of their cars.

But his interpretation of the law has never been tested in a Canadian court. The only case law authorities can cite comes from a 1992 decision in Scotland's version of the Supreme Court. It found use of the boot to be a form of extortion, stating: "It is illegal for vehicles to be held to ransom."

Police say booting cars is a crime

Officials within the Edmonton Police Service say there is no intention to back down from their position that putting boots on vehicles is a crime. The partners who own RFM Parking say they'll continue with what they consider a legal practice.

Cantwell currently faces two mischief charges, and a senior Crown prosecutor has been assigned the case — so it appears a much needed legal decision will eventually be made.

In the meantime, the cat and mouse game between the parking patrols and police will continue. After her latest brush with police, Deanne Elliott faced neither jail nor any new charges. That's because the owner of the vehicle on which she had put a boot paid the $300 fine, and had the device removed.

After the three police officers affirmed she was free to go, she remarked: "Good day. I didn't go to jail and hopefully it's not tomorrow either."