There is no universal definition for a long-term missing person. Different investigating agencies may have different timeframes or mandates that define “long-term”. In addition, various state and federal laws[1] may legislate the period of time passed when an agency should enter a missing or unidentified person case into NamUs. Case circumstances may also warrant the entry of a missing person case into NamUs; however, that entry is at the discretion of the investigating agency. Operationally, NamUs considers cases greater than 180 days as “long-term.” This is a shorter time frame but still consistent with NIJ’s National Best Practices for Implementing and Sustaining a Cold Case Investigation Unit definition of a “cold case” and other recommendations.[2]
In fact, the NamUs database reflects that in 2023, greater than 90% of missing person cases in NamUs are older than 180 days and 40% are older than 20 years. Users should consider this timeframe when adding a case to NamUs.
[note 1] Billy’s Law, S.5230, 117th Congress (2021 – 2022), 2022, https://www.congress.gov/bill/117th-congress/senate-bill/5230/text/pl .
[note 2] White House Domestic Policy Council, U.S. Department of Interior, U.S. Department of Justice, Not One More: Findings & Recommendations Of the Not Invisible Act Commission, November 1, 2023, 47, recommendation B3, 34 NIAC Final Report version 11.1.23_FINAL.pdf (justice.gov).