Alexandria police are looking in the Washington gay community for clues to the weekend slaying of Ray Heidebrecht, leafleting bars in the Dupont Circle and Southeast Washington areas, where he is known to have been a patron, police said yesterday.

"Investigators are concentrating on establishments in the Washington area that our victim may have visited," said Lt. John Crawford, a spokesman for the Alexandria police.

Heidebrecht, who lived alone, was found dead in his house early Monday morning by a neighbor who alerted police. An autopsy yesterday confirmed that the 39-year-old Marine Corps civilian computer specialist died of a single stab wound.

Police said Heidebrecht was slain in his house, in the 300 block of LaVerne Avenue, and the neighbor who discovered the body said there were no signs of forced entry. Police said there was also nothing at the scene to suggest that the stabbing was a hate crime.

"Simply because a person is a member of a minority doesn't give us reason enough to believe they were targeted for that reason," said Alexandria police spokeswoman Amy Bertsch.

Heidebrecht's maroon 1999 Isuzu Rodeo, with Virginia license plates YTG 7844, is still missing.

Scott Fidler, who discovered Heidebrecht's body, and other neighbors in this close-knit Alexandria neighborhood sat together in stunned grief yesterday, drying tears and reminiscing about their friend, who they said was the heart of their community.

"He lifted your day up," said neighbor Cheryl Bates. "On this block, if you were having a bad day, he lifted you up."

Fidler last saw Heidebrecht on Saturday afternoon. Over the weekend, Fidler grew concerned. There was no sign of the car, and the porch light had not been turned on, Fidler recalled. Heidebrecht was diabetic, and as a safeguard, the across-the-street neighbors established the porch light as a means of silent communication.

When Fidler returned home early Monday morning, police said, the porch was still dark, so he walked over to check on his friend and found his body. Fidler said yesterday that Heidebrecht's front and back doors were unlocked when he went to the house.

Yesterday, Fidler and his neighbors remembered Heidebrecht as a generous friend.

"He was the coolest white man on this whole street," said teenager Steven Bates. "He had no negative parts of his whole attitude."

Bates looked down at his knee, which bore a scrape from a moped accident. Heidebrecht patched it up with antibiotic ointment and a band-aid, he said.

Neighbors said Heidebrecht sometimes had helped youths at a state-run home for troubled teenagers down the street with homework and with driver's license preparation.

His ability with computers was legendary. He even rebuilt computers from spare parts for young neighbors, including Bates.

Eric Davison, an old friend of Heidebrecht's, said his generosity extended to fixing friends' cars as well, a talent he had honed in a previous job at an Arlington car dealership.

Bruce Johnson, a board member of the Washington-based group Gay Men and Lesbians Opposing Violence, said the mysterious death has put a chill on the community. "People are being a little bit more careful," he said. Police are offering a reward of up to $1,000 for information. The tip line is 703-838-5033.