However, the reasons for the decline remain unclear, and at least one expert is questioning the accuracy of the numbers.
According to National Crime Information Center statistics released Tuesday by the FBI, 719,558 missing-person records were entered into NCIC last year, down 7.5 percent from 2008. In the related category of unidentified persons, 1,040 cases were entered last year, or 8.2 percent fewer than in 2008.
"The total number of missing person cases has been declining for some time now," NCIC supervisory technical information specialist Monte McKee told AOL News. "We really don't have an answer, and it's more speculation than anything, but the impression is when the economy improved, it seemed to help. There's [also] more awareness of potential threats to kids now."
Todd Matthews, regional system administrator for federal records clearinghouse the National Missing and Unidentified Persons System, attributes the decline to both greater awareness of missing-person cases and improved technology.
"Legislative efforts are making a very positive impact on awareness and training needs in the law enforcement community," Matthews told AOL News. "Marked improvements in DNA collection and processing are also bound to impact and contribute to the overall status of missing and unidentified persons."
All in all, Matthews says he believes the new numbers are a clear indication that the "major battles in the war on the missing are being won."
Not everyone, however, is convinced there's reason to celebrate.
"As long as I continue to learn of agencies that are not aware of Suzanne's Law, I will continue to doubt the accuracy of these statistics," Kelly Jolkowski, founder of Omaha, Neb.-based missing-person assistance group Project Jason, told AOL News.
Suzanne's Law is a federal law that requires local police to notify the NCIC when someone age 18 to 21 is reported missing. Previously, police were mandated to only report missing persons younger than 18.
"Any system is only as good as the persons utilizing it and ... their knowledge of related laws," Jolkowski said.
She also pointed to National Incidence Studies of Missing, Abducted, Runaway and Thrownaway Children, or NISMART, which reported there were well over a million runaway or "thrownaway" youth in 1999. Unlike runaways, thrownaway children are those who have been told to leave home, or been abandoned; kids in both groups are often not reported missing.
Missing adults may be left out of the stats as well, Jolkowski said. "We know there are approximately 3.5 million persons per year experiencing homelessness, and that is just one segment in the throwaway adult category," she said. "While some of these persons may not technically be considered 'missing,' many others would qualify."
The current criteria for missing persons include those who are missing after catastrophes, or under circumstances indicating that they may be in physical danger or that their disappearance may not have been voluntary.
McKee said he does not believe there are problems with the reporting, and points to efforts made to ensure their accuracy.
"[The statistics] are based purely on what is reported to NCIC. If they are not reported, they're not included in the list," he said. "We have an audit staff that goes out, and each [law enforcement] agency is audited every three years. As far as I know, we don't think that is a really big problem at this point."