Missing, Abducted, Runaway, and Thrownaway Children (NISMART–2) study by the U.S. Office of Juvenile Justice and Delinquency Prevention from 2002 comprehensively described missing children cases for year 1999. The study considered a child missing when the child's whereabouts were unknown to the primary caretaker, with the result that the caretaker was alarmed for at least 1 hour and tried to locate the child. The estimated number of "caretaker missing children (reported and not reported)" was around 1.3 million, with about 800 thousand missing children estimated to have been reported. The 1,300,000 number is further broken down into approximately 33,000 non-familial abductions, 117,000 familial abductions, 629,000 runaway/thrownaway cases, 198,000 lost/injured, and 375,000 "benign explanations". By the time the study data were collected, 99.8% of 1.3 million caretaker missing children had been returned home alive or located. Only 0.2% percent or 2,500 had not, the vast majority of which were runaways from institutions. Furthermore, only an estimated 115 of 33,000 non-familial abductions were stereotypical kidnappings, involving a stranger or slight acquaintance, who holds the child for ransom, abducts with intent to kill or keep permanently. Data in the study was derived from a Law Enforcement Study, National Household Surveys of both Adult Caretakers and Youth (telephone interviews) and a Juvenile Facilities Study. The estimated number of 800,000 missing children reports has been widely circulated in the popular press. The United States' National Crime Information Center (NCIC) of the Federal Bureau of Investigation, mandated by the National Child Search Assistance Act, maintains its own "Missing Person File" to which local police report people for whom they are searching. The NCIC "Missing Person File" does have a category that is entitled "Juvenile" or "EMJ" (for: Enter Missing Person - Juvenile), but that category does not reflect the total number of all juveniles reported missing to the NCIC, for whom local police are searching. The NCIC also uses its own classification criteria; it does not use the above NISMART definitions of what constitutes a missing child. The NCIC data is limited to individuals who have been reported to the NCIC as missing, and are being searched for, by local police. In addition, the EMJ category does not contain all reports of juveniles who have been reported missing to the NCIC. While the EMJ category holds records of some of the juveniles reported missing, the totals for the EMJ category excludes those juveniles recorded missing but