AUGUSTA — A few months ago, a veteran police officer in Windsor, Conn., noticed something strange on the streets of his community — a lot of cars with Maine plates.

What he discovered was a scheme by Connecticut drivers to avoid paying local property taxes by registering their vehicles in Maine through the state’s online system.

Drivers in Connecticut cannot register their car if they owe property taxes, according to Officer Russ Wininger of the Windsor Police Department, a community just north of Hartford, Conn.

“It flags you so you can’t register your vehicle,” he said.

To skirt the law, police are finding drivers in Connecticut who register their cars in Maine instead, via online, third-party services.

“They send in the payment, power of attorney and the little release form, and these companies send out marker (license) plates,” Wininger said. “It may be legal in Maine, but in Connecticut, it’s against the law. It’s a $1,000 fine.”

And it seems to be popular. There are more than 1.5 million cars, trucks, buses, trailers and motorcycles registered to Mainers. Of the approximately 2,400 out-of-state motor vehicles registered in Maine, according to Secretary of State Matthew Dunlap, just over 900 — close to 40 percent — have a mailing address in Connecticut.

“It’s not a huge number, but it’s a burr under their skin,” Dunlap said about officials from Connecticut and other states. “We’ve talked about this. We do it as a convenience for people who have a summer property here and keep a vehicle here and register their vehicles here.”

For Connecticut officials, this system is more than just a nuisance. They know about the registration scofflaws but have a hard time tracking them down, according to Bill Seymour, spokesman for the Connecticut Department of Motor Vehicles.

“They are illegally circumventing our registration laws and denying towns and cities the property taxes legally owed to a municipality,” Seymour said. “Other states should not condone this action. Finding scofflaws is very difficult because their out-of-state license plates look like any other that is legally here from another state.”

When found, not only do the registration offenders get a ticket from police for illegally registering their vehicles out of state, they also are reported to their local assessing departments, which can take further action, Seymour said.

“Municipalities should use their enforcement powers to monitor reports of violations and then issue a summons to any Connecticut resident flouting our laws,” he said. All cars garaged in Connecticut for more than six months must be registered in that state, the spokesman said.

Wininger said he recently stopped a person, driving a car with a Maine license plate, who owed more than $4,000 in back property taxes. Those debts add up for communities, the officer said.

“I don’t know what is going to happen down here,” Wininger said. “The best solution is for your state to stop doing it.”

‘Huge convenience’

It’s not hard to understand why Maine continues to offer the service.

Maine receives about $100,000 annually from out-of-state vehicle registrations and an additional $350,000 in municipal excise tax, Dunlap said. The state also receives revenue for vehicle titles and a small amount from sales tax.

The state doesn’t actually run the online registration, which was established more than two decades ago in order to register fleets of interstate commerce vehicles, Dunlap said.

Per state regulations, third-party agents offer the service. The biggest agents in Maine are the Staab Agency of Jefferson, Haskell Registration of Augusta and Maine Motor Transport Association Services Inc. also of Augusta.

The agents for the Maine Department of Motor Vehicles also register trailers — big rigs and smaller rigs hauled by personal vehicles — which in recent years has brought in between $6 million and $15 million in revenues, Dunlap said.

“We register fleets of tractor-trailers,” Dunlap said. “Other states hate it, but trucking companies love it. It’s not just cheap, it’s a huge convenience for tractor-trailer companies.”

The online service allows companies to process anywhere from one to 100 registrations at a time, with vehicles for one year and trailers from one to 12 years, according to Brian Parke, Maine Motor Transport Association president and CEO.

The Augusta company handles mostly tractor-trailer registrations, with a few Maine-based vehicle fleets and a small number of out-of-state personal vehicles, he said.

“It’s very inexpensive and convenient to do this in Maine,” Parke said. “(Those registering vehicles) need (to provide) proof of ownership, obviously, a copy of the power of attorney form because (third-party agents) can’t do work on behalf of someone without one, and you also have to have a release form as well.”

The release form, which is provided on each of the agent’s websites, states the person registering a car or trailer in Maine acknowledges “they understand that the laws in their home state may require them to register the vehicle(s) there” and that Maine agents cannot be held accountable.

To register in Maine, vehicles or trailers from model year 1995 or newer must be titled in Maine, which is another service the agents offer. Sales and excise tax also need to be paid, if not already paid to the registrant’s home state.

The simple applications are available at each of the agents’ websites. Those registering trailers fill out their name and pertinent information — the vehicle make, model and vehicle identification number — and select the registration years. Those registering vehicles can provide basic information online or call for a quote.

At the end of the online forms, there is a final note that warns registrants if they “have not paid sales tax in your state, it is your responsibility to pay Maine sales tax.”

Excise taxes from out-of-state vehicles go into the state revenue fund and registration fees go to the highway fund, said Garry Hinkley, Maine Vehicle Services Division director.

Dunlap pointed out that Maine is victimized by other states, most notably New Hampshire, where there is neither sales or excise tax.

“In Lebanon [Maine], so many people were registering their cars in New Hampshire that they look for New Hampshire (license) plates in driveways,” he said. “Wherever you go, people are creative in finding ways to save money.”

But this sentiment doesn’t hold for Wininger. His goal is to educate other police officers in Connecticut to be on the lookout for illegal Maine registrations.

“What you are doing really should be revisited — you’re killing us down here,” he said.