Peter T. Nguyen has lived for five years in a brick house with a manicured lawn in Arlington County's idyllic Madison Manor neighborhood. A collection of exotic and deadly snakes has lived there too.

The serpents, stacked neatly in clear plastic containers under warming lights in his garage, have unnerved neighbors, who blame Nguyen for a series of snake sightings in the area. On Saturday, the Arlington County board unanimously passed a ban on poisonous reptiles that was inspired directly by what Nguyen's neighbors refer to as "the Snake House."

Two years ago, Madison Manor resident Larry Koskinen stepped on a venomous rattlesnake in his garage. Barb Misra spotted a five-foot snake in her garden. And last week, a 4-year-old nearly ran over an exotic serpent on the sidewalk with her doll stroller.

Nguyen denies those snakes came from his house, and no one can prove otherwise.

But a March incident in which a plumber showed up at Nguyen's house to fix a broken hot tub and found containers of dead snakes on the porch convinced county officials to move swiftly to enact the ban.

"This is not one of the harder votes that I've had to make," board member Jay Fisette said after the vote.

Nguyen has 30 days to get his poisonous snakes out of the county.

"This isn't about snakes," said Koskinen, a father of three, who lives next door to Nguyen. "This is about protecting our children. That my neighbor has something from Mexico or Africa that could kill my child violates the social compact in a profound way."

Two of the loose snakes were found next door to Nguyen's house and one was found in a yard that backs up to his. Still, Nguyen insists it would be "an impossibility of physics" for the snakes to have been his. He said he doesn't collect those species, favoring instead rare African pit vipers. The snakes he does collect are kept in the kind of plastic containers used in labs to hold rodents, secured from the outside with bolts.

On March 11, a plumber came unannounced to Nguyen's house to fix the leaky hot tub. When he spied 20 or so dead snakes in containers nearby, he called 911. Within minutes, police cars and an animal control van arrived. Nguyen said he refused to let the officers in; he hadn't done anything wrong. He said he explained that he had taken the dead snakes out of the freezer, at a researcher's request, to begin to "skeletonize" them.

Officers milled around Nguyen's property for more than five hours and peered through the windows of the garage with a scope.

The District of Columbia, Falls Church, Fairfax City and Prince William and Prince George's counties ban possession of venomous snakes. Under Arlington County code, it was previously illegal only to "display, exhibit, handle, or use any poisonous or dangerous reptile in such a manner as to endanger the life or health of any person."

Nguyen, 39, is a quiet, private man who writes and edits advertising copy. He says he knows few people understand his lifelong hobby.

Since the plumber incident, Nguyen said he has been quietly moving his snakes to other locations. He won't say where, but he has promised the county can inspect his house to make sure the collection is gone.