hen Svetlana Aronov, a 44-year-old rare-books dealer who lived on the Upper East Side, disappeared on March 3 while walking her father's dog, the Police Department mobilized. The commander of Manhattan detectives held a news conference with a giant photograph of the missing woman.

When Ramona Moore, a 21-year-old Hunter College student who lived with her parents in East Flatbush, Brooklyn, did not come home on April 24, the department's public information office made no mention of the young woman until her body was found.

Ms. Moore's relatives, immigrants from Guyana, now say that the police did not give her disappearance the same attention that they lavished on Ms. Aronov's. "They even handled the dog better than they handled my niece's disappearance," said Patrick Patterson, Ms. Moore's uncle. "But I guess we don't probably pay enough taxes like anybody else."

Michael P. O'Looney, the Police Department's chief spokesman, said that the different treatment had to do with circumstances, not with race or class. Ms. Aronov, he said, was the mother of a young girl, she left the house with only her keys and a cellphone, and her father was expecting her to pick him up at the airport.

"Based on that, there are some red flags that are immediately raised that tell detectives that something is wrong," Mr. O'Looney said. On the other hand, he said, young adults often disappear for days at a time.

But Ms. Moore's parents were sure that something had happened when she did not return from a friend's house. To them, their only child was not a full-fledged adult but a young person finishing her education. "She never stayed out," Mr. Patterson said. "If she's running five minutes late from the library, she calls." On the third day she was missing, Mr. O'Looney said, the police began a full investigation, using bloodhounds, interviewing friends looking at phone records, even trying to track down an ex-boyfriend.

Neither Ms. Moore nor Ms. Aronov had a history of serious mental illness or a criminal record. Last year, there were 25 murders in the precinct where Ms. Moore lived, and 3 in Ms. Aronov's precinct. Ms. Moore's bludgeoned body was found a few blocks from her home. Ms. Aronov's was found in the East River. It has not been determined whether she jumped, slipped or was pushed.

Eugene O'Donnell, a professor of law and police studies at the John Jay College of Criminal Justice, said that different treatment was legitimate, to a point. "No two cases are alike," he said. But, he added, there are more resources, and news media attention, devoted to crimes in Manhattan than in other boroughs. "It's a longstanding problem," he said.

Mr. O'Looney said the department must divide its resources among many disappearances — nearly 7,200 last year, many of them runaways or people with Alzheimer's disease. The police release a photograph when the investigating squad believes it will help, he said. "It's a judgment call," he said of Ms. Moore's case. "They're looking back; would a press conference have helped? Maybe it would've."