Roy Carter Jr., inspector of weeds and rubbish for Montgomery County, slid his car up to the curb and checked a file. As always, the complainant was "anonymous." He zipped up his pale yellow windbreaker and moved in.

Nobody answered the door. Carter went next-door, but again there was no answer. He tried a house on the other side. A woman answered and let him in. He went out the back door of her house and peered over the fence. "The guy's got a jungle for a back yard," he said.

Down the street, in another Wheaton subdivision, the suspect was described as "very hostile." He has two vans and a car in the yard and none of them has wheels. Carter said the yard had been a problem for a long time and now the case was going to court. "His luck ran out," Carter said. "We have him nailed."

Montgomery County residents with junky and unkempt yards have been nailed with increasing efficiency in the last six months, as changes in the county code decriminalized many environmental, housing and health violations and allowed county agencies to take civil action against offenders.

The old system "didn't work at all," said County Council President David L. Scull. "Judges will not give people a criminal record for letting the grass grow too long, or the paint on the shutters peel. . . . There was a growing hard core of offenders that knew there was no real threat. They could thumb their noses. The bottom line was that a judge wasn't going to do anything to them."

There has been no increase in the number of persons brought to court since the law changed, Scull said, but there has been an increase in the number who are obeying the law. He suggested that one of the main reasons is that people believe action will be taken against them if they don't comply.

In most enforcement departments, those who disobey regulations are sent warning letters. If nothing happens, they are then issued "citations" that are similar to traffic tickets. In the county's Department of Environmental Protection, citations include a $50 ticket for grass and weeds higher than 12 inches, and $250 tickets for inoperable cars abandoned more than 30 days. Previously, owners of overgrown lots could receive a $100 fine, and owners of abandoned cars were liable for fines up to $1,000 and six months in jail.

The department employs two full-time and two part-time inspectors. Although his department receives about 300 complaints a month, almost always from neighbors, Carter said that only a handful of tickets are issued. Assistant County Attorney Adam J. Wojciak said he normally prosecutes fewer than a dozen a month.

"The vast majority of people I come in contact with are normal, law-abiding, God-fearing people," Carter said. Most of them will clear up the mess when it is brought to their attention, but not all of them, he said. "You see pathetic people, mental cases, people who are antigovernment, antiauthority, professional people who think they are above the law."

Carter recalled visiting a wealthy professional in Potomac whose sons spent their spare time working on wrecked cars in the yard. The father protested the intrusion of the inspectors, telling Carter, "I'd rather have my kids here working on cars than smoking drugs in a shopping center."

On the other hand, Carter said, inspectors must avoid making aesthetic judgments. One inspector was called to investigate a complaint that a woman had a toilet bowl in her front garden. But the woman insisted it was a flower pot. Because it was filled with soil and flowers, the inspectors allowed her to keep it.

Carter's supervisor, George E. Pace, said inspectors try to avoid confrontations and try not to be petty. Carter, for instance, carries a ruler with him but rarely uses it to measure the height of weeds. And if a person is honestly unable to clean up the rubbish, inspectors will give him time and try to find him help.

Often there are "underlying problems," Pace said, such as "people who are very old and living alone, not having any friends and maybe not even wanting any." In such cases, Pace said, he will ask social service agencies for help.

Lenus D. Barnes, chief of solid waste regulation for the environmental department, said most people quickly correct problems once they are told they are breaking the law. Others resist the intrusion of government inspectors, however, and need the threat of a citation and fine to clear up the mess.

Barnes said inspectors try to be accommodating, listening to excuses and making suggestions on how to clean up. "We'll give them a period of time to do whatever they say they're going to do with their valuable heirloom," he said. "In the vast majority of cases, it's just plain rubbish and folks haven't kept Montgomery County beautiful."