D.C. police have not kept comprehensive statistics on missing adults since 1995, a lapse that has prevented investigators from knowing whether the disappearance of Chandra Levy has anything in common with hundreds of other missing-person cases in the city.

Executive Assistant Chief Terrance W. Gainer said the missing-persons unit was decentralized six years ago, leaving each of the city's seven police districts to handle cases internally. Since then, there has been no consistent record-keeping and no systematic approach to tracking how many adults are missing and how many are found.

"Consequently, there [are] not good citywide records of who's missing, who's come back and any patterns," Gainer said. "You're going to have difficulty managing the problem if you don't have some sense of the problem."

Gainer said that when Levy disappeared last month, thrusting D.C. police officials into a case that drew national attention, they asked themselves some obvious questions:

Did any of the other missing-person cases in the District share similarities that might help them solve the disappearance of the 24-year-old former intern? And was as much attention being devoted to those other missing adults?

Police were dismayed to learn that they could not answer either question.

Without good case records, Gainer said, it's also difficult for police officials to gauge how well detectives are handling missing-persons cases.

The implications for relatives of missing adults can be profound.

"Families need to know that law enforcement is really utilizing technology to assist them," said Kym Pasqualini, president of the Nation's Missing Children Organization & Center for Missing Adults. "When missing people fall through the cracks [of a police investigation], it can be devastating to family members."

Gainer said the inability to compare missing-persons data has not hampered the Levy investigation. "I don't think [knowing the data] would hurt, but I don't think it has interfered," he said.

But last week, after inquiries from The Washington Post on whether police missing-person records showed any cases similar to Levy's, Gainer issued a directive to officers to begin reporting all missing-adult cases to each district's regional operational commander. In addition, he asked police statisticians to compile a list of the city's missing adults that includes their age, race, gender and the length of time since they disappeared.

Based on recent visits to each of the seven police districts, police determined that 558 of the missing-person cases reported this year are still open and that about 160 of those involve juveniles. But Gainer said those figures may be inaccurate.

Police officials, he said, found that the 3rd, 4th and 5th districts had "poor record-keeping" and that the other districts' records were no better than "decent." There also was very little communication between officers of different districts, he said.

The only other overall count of missing people in the District comes from the FBI's National Crime Information Center database. But those records may also be unreliable, Gainer said, because although a name is entered in the database whenever D.C. police open a case, it is not always removed when the case is closed.

"My hypothesis, based on the records I've seen, is that we probably have a lot more missing people in the federal computer system than should be there," he said. According to the FBI records, 443 of the D.C. residents reported missing this year have yet to be found.

Over the next month, Gainer said, all officers will be reminded at roll calls that whenever a missing person is located, the paperwork to have the case pulled from the FBI database must be filled out.

D.C. Chief Medical Examiner Jonathan L. Arden, whose office examines unidentified corpses, routinely gets called when police receive a report of a missing person. He agreed that the police department's system for tracking missing adults needs improvement. "The lack of a coordinated system on their part and our part creates a potential problem," Arden said.

The lack of centralized records affects not only the Levy investigation but also scores of lesser-known cases, such as the search for 44-year-old Freddie Wallace, last seen Dec. 13 at his residence on Jefferson Street NE, or 76-year-old Diana Benjamin, who disappeared from the 300 block of O Street SW in August.

Police officials elsewhere in the Washington area said they have comprehensive, readily available statistics on missing adults.

D.C. police officials decentralized the unit for missing adults during the tenure of Larry D. Soulsby as police chief. But they left intact the unit for missing juveniles. This year, all but 81 of the 1,884 youths reported as missing have been located, said Sgt. Robert Garaffo, who oversees that unit.

Gainer said he did not focus on missing-adult trends until he had an "epiphany" with the Levy case. "When we were putting all these resources [on the case], it was very natural to ask: 'Are we treating this case any different than any other case?' " he said. "And in order to make that determination, you had to find out what your base line was, and that was when we found out the base line wasn't there."