With Christmas, Hanukkah, and Kwanzaa approaching, your home may attract more visitors than usual. Not all of them will be bearing gifts, fruitcakes, or good cheer—some want to take what's yours.

So goes the tale of a Consumer Reports editor who, with his wife and three young daughters, fell victim to a thieving Grinch in mid-December 2005. His New Jersey home is equipped with a state-of-the-art security system, but a major "flaw" in security was exposed that cold, gray day: The homeowners neglected to arm the system in the mad rush to get the kids to school and themselves to work. About 30 minutes after everyone had left the house, a burglar smashed a rear window to enter the four-bedroom 1927 Tudor, ransacked the master bedroom, and made off with loot that included heirloom jewelry, electronics gear, and $2,000 in cash intended as various holiday gifts and tips.

"We felt like such fools for not having used the alarm," says the wife, who admits that before the break-in, she and her husband would not always activate the system during the workweek. "Our nanny was due at the house in the late morning, and we never imagined someone would target our place in broad daylight. The police detective did say there's a chance the alarm would have scared off the crook. But he also told me that even if the alarm had gone off, the thief still probably would have been in and out of the house before the patrol car could have rolled up—he was likely inside for less than 5 minutes."

Unfortunately, the editor's story is not uncommon, according to Michelle Boykins, director of communications for the National Crime Prevention Council. "During holiday time you certainly have to be more aware," says Boykins. The hustle and bustle of this time of year can make even the most careful person forget to take basic safety precautions. Distracted homeowners provide perfect openings for thieves to steal a family's holiday joy. "It's a great opportunity for burglars when they know gifts are being wrapped and hidden and people aren't always taking the precautions they should," Boykins says.

According to statistics from the Federal Bureau of Investigation, summer is peak burglary season. But Jean O'Neil, the NCPC's director of research and evaluation, says that in her experience, crime-investigation professionals anecdotally "note a definite uptick during the stretch between Thanksgiving and New Year's." The few minutes it takes to deliver gingerbread to a neighbor, she warns, is all that's needed for a professional thief to open an unlocked door and take everything under the tree.

To keep thieves from souring your holiday cheer, follow our advice: