A prominent international economist and his wife were found murdered late Friday night, both shot in the back in the family room of their $200,000 house in an exclusive Fairfax County subidivision near Tysons Corner.

Police authorities investigating the deaths of Morton C. Grossman, 62, and his wife, Sylvea, 58, said burglary is a possible motive in the double slayings. Grossman, an independent consultant to the World Bank and several foreign countries, was an avid collector of antiques. Sylvea Grossman operated a small antique store in Bethesda.

"It looks like whoever killed them was interrupted," said Fairfax County police spokesman Bill Brown. "It looks like they were scared off."

Brown said police found no signs of a struggle or forced entry into the home only the couple's Siamese cat, Pepe, "wandering around the house." However, several pictures had been taken off their hooks and left leaning against the walls "like somebody was going to come back for them."

The bodies were discovered lying face down a few feet from each other in a ground-floor room off the main foyer. A basement patio door was found unlocked.

Police were called to the scene around 9:20 p.m. Friday after the Grossmans' daughter and son-in-law, vacationing in Williamsburg, had tried most of the day to reach them but had found the phone line continuously busy. The Grossmans had last been seen by neighbors Thursday night. That night Montgomery County police were called to what they reported as a false alarm break-in at the Sylvea Grossman Gallery in Bethesda.

"It's hard to imagine how something like that could ever happen to him," said a friend and neighbor, who asked not to be identified. "Mort never even raised his voice."

News of the murders shocked residents of the Wolf Trap Woods subdivision, a cluster of expensive colonial-style houses separated by well-tended lawns, oaks and scrub pine and home to many upper-level government workers, consultants, union leaders and at least four Secret Service agents.

"It's not the kind of thing you expect to happen in your neighborhood," said one resident. "You know, you see it all the time on television, but it's always far away. Like Vietnam -- it isn't real."

Grossman, an independent expert in international economics and former Harvard University professor, was described by neighbors as a mild-mannered intellectual who kept meticulous care of his home and belongings. mHe was the finance chairman on the local homeowners association, paying $72 in annual dues for upkeep of the subdivision's three private tennis courts and common grounds.

He spent several months a year traveling around the world. When he was home, said next-door neighbor and Miter Corp. executive Richard Nixon, Grossman was seen most often taking care of his lawn, which, like Nixon's, was tended several times annually by a professional lawn service.

"He cared about his place," Nixon said.

Like Nixon, the Grossman's had moved into their two-story, red brick tract house three years ago, visiting the construction site almost daily for the six months it was being built. He kept an office in the basement and shared a blue BMW automobile with his wife.

In the garage, Grossman built a private entrance for the cat, Pepe, who wandered freely around the neighborhood when the garage door was left open.

"I probably saw the cat more often than either of them," Nixon said.