It takes Sgt. Charles Denault barely two minutes to spot a dozen cars with out-of-state license plates parked in driveways and outside houses and apartments.
Driving his cruiser along this streets of coastal Kittery, Denault is on the lookout for vehicles registered in other states — especially New Hampshire — but owned by people who live in Maine.
"They're everywhere," Denault said as he points out car after car with New Hampshire plates. "It's like dandelions that keep popping up."
By professing to live in New Hampshire, Mainers can avoid paying a 5 percent sales tax when they buy a vehicle. They also don't have to buy car insurance, which is required in Maine but not in New Hampshire. And people who work in New Hampshire can also avoid paying Maine's income taxes if they claim a New Hampshire residence.
A side effect is that they may end up paying slightly more to register their car in New Hampshire — a negligible worry for Mainers already skipping out on paying other taxes but potentially devastating to towns like Kittery, which hurt as tax collections and state aid to the town go down.
Police say some people simply aren't aware that they're required by law to have Maine plates after 30 days of becoming a resident. But all too often, said Kittery Police Chief Ed Strong, money is the motivator.
Strong said offenders use all sorts of tricks to get around the law: Some claim to live at a relative's New Hampshire home or use the address of a rental or seasonal property.
"We have found people that have dummy addresses in New Hampshire to register their vehicles," Strong said.
Nobody knows for sure how many excise tax evaders there are in Maine or how much money the state and local towns are losing because of them.
In Maine, it would cost $305 in excise taxes and fees to register a 3-year-old midsize car with a retail price of $20,000; the same vehicle would cost $313.20 to register in New Hampshire.
Kittery police typically write 150 to 200 summonses a year for excise tax evasion, although the pace has accelerated over the past year.
But other towns aren't so vigilant.
Maine Revenue Services issued a report last year that concluded excise tax enforcement is a low priority in most of Maine's border towns.
Still, at the request of the Legislature, the agency this summer appointed an agent to work with municipalities to help them identify scofflaws, said Errol Dearborn, who heads the enforcement division of Maine Revenue Services. The aim is to boost excise tax collections on the local level and sales tax collections for the state.
Everybody ends up paying to make up for the people who are scamming the government out of taxes, Dearborn said.
"It's tough on the people who are paying their excise taxes, and it's tough on everybody's property tax," he said.
On Kittery's streets, Denault says, he knows which cars with New Hampshire plates belong to workers who only come to Maine for their jobs and which cars show up night after night at the same house or apartment.
On a recent November morning, Denault knocked on people's doors and handed out a half-dozen summonses. One woman told him the car with New Hampshire plates in her driveway was owned by her sister who was visiting, but she later came out of her house to admit she was lying.
Each summons carries a potential fine of $911. If a person also doesn't have a Maine driver's license, the fine can jump another $137.
Ian Thomas, a 27-year-old cook, was one of the unlucky ones, getting a ticket because his car has a North Carolina plate on it. Thomas said his mother gave him the car a couple of years ago, but it's still registered in her name in her home state. He said he didn't know he had to register it in Maine.
"It's quite a hit," he said as Denault wrote him a ticket that could cost him nearly $1,000. "If I'd known, I would have registered it here sooner."
Not everybody's as honest, Denault said. Some people hide in their home when they see him coming. Others claim they don't live there. Or they lie about who owns the car parked outside.
"Some people say, 'This isn't fair. This is harassment,'" Denault said. "But it's a clear-cut violation of the law."
Maine isn't the only place to crack down on excise tax offenders. Border towns in Massachusetts also are on the lookout for people who illegally register their cars in New Hampshire. Police in Lawrence in the past have cracked down by towing away offenders' cars.
Denault doesn't plan to go that far, but he doesn't intend to stop cracking down, either.
"The problem's getting worse," he said. "And these people are getting a free ride."