About 600 residents of the Aspen Hill area of Montgomery County, where 16 women have been sexually assaulted in the last year and a half, gathered last night at the Earl B. Wood Jr. High School to find out what progress police are making in their investigation.

County Police Chief Bernard D. Crooke told the crowd that turned out for the school's PTA meeting that usually attracts only 100 to 200 persons that the rape investigation has become his agency's top priority and that, if the community cooperates, the rapist will be apprehended.

He said one key to preventing further assaults is neighborhood unity -- that neighbors should get to know each other and report to police the presence of strange cars and people.

Det. John Cady, one of four primary investigators assigned to the rape cases and one of several dozen officers now working on the case full time, said that so far police have only a vague description of the attacker. The description of a white man between 18 and 25 with a medium build and possibly brown hair "fits about 60 percent of the population," Cady said, "but it's all we have. What you've seen on television about how police use fingerprints is totally out the window. This man wears gloves."

Dean Leipsner, a 17-year-old resident of the Aspen Hill area, said police have stopped him twice in the last two weeks to question him as a suspect and asked if all young men like himself who resemble the description can expect to be stopped.

The answer was yes, and he was told he will probably be stopped and questioned again.

Alice Goldberg said she was frustrated as she left the meeting. "The police didn't say enough about what we women should do if we're confronted by this man. I'd like to know more about his psychological profile. Should we be aggressive or passive if we're confronted by him?"

Officer Stanley Wills, who presented a series of slides showing ways to make a home more secure, said that residents through the area have organized Neighborhood Watch groups to watch neighbors' homes and to be on the lookout for unfamiliar people and vehicles.