Thieves who a year ago selectively took more than $1 million in expensive silver and jewels from wealthy Washington-area homeowners have burglarized the homes of at least 14 Northern Virginia families since Thanksgiving, police reported yesterday.

The thieves have stolen between $8,000 and $10,000 in silver and gems during each of nine burglaries in McLean since November, although they have left behind costime jewelry and silver-plated items, according to the commander of the McLean substation, Capt. Ronald Watts.

Although the burglas have hit McLean the hardest, Watts said two such burglaries in Groveton, two in Reston and one in Arlington New Year's Eve also have been reported since November.

FBI agents and local police who formed a special unit to investigate the burglaries thought the thefts had stopped because no incidents had been reported since last August, Watts said.

But Watts said, "they haven't stopped. They'll hit a couple (homes) in this area, then the next couple times they'll go to Falls Church or Arlington. There's no predictable pattern."

Watts said the thieves hit between 5 and 11 p.m. while most burglars commit their crimes in the daytime. The families are never at home.

The thieves typically ransack the homes and are often heard jostling furniture around by neighbors who do not report the incidents until it is too late, Watts said.

After stuffing the items in pillow cases taken from beds in the home, the burglars load the goods in the family car, if they have been able to find the car keys. They then drice to a designated spot and unload the silver into another vehicle and abandon the theft victims' cars, Watts said.

None of the stolen items in any of the silver burglaries has been recovered, Watts said.