The Second National Incidence Studies of Missing, Abducted, Runaway, and Thrownaway Children classified kidnappings as either family or non-family abductions.
Family abduction was defined as the taking or keeping of a child by a family member in violation of a custody order, decree, or other legitimate custodial rights, where the taking or keeping involved some element of concealment, flight, or intent to deprive a lawful custodian indefinitely of custodial privileges.
Non-family abduction was subdivided into "stereotypical kidnappings" which fit the public stereotype of the crime, and legal definition abductions, which are generally short-term forced movement or detention of children to facilitate another crime such as robbery or sexual assault..
- In 1999, there were an estimated 115 "stereotypical kidnappings," defined as abductions perpetrated by a stranger or slight acquaintance and involving a child who was transported more than 50 miles and detained overnight, held for ransom or with the intent to keep the child permanently, or killed.
- In 1999, there were an estimated 58,200 child victims of non-family abductions, defined more broadly to include all non-family perpetrators (including friends and acquaintances as well as strangers) and crimes involving lesser amounts of forced movement or detention in addition to the more serious crimes entailed in stereotypical kidnapping.
- In 1999, there were an estimated 203,900 child victims of family abductions, of which 43% were not considered missing by their caretaker because they knew their child's whereabouts or were not concerned by the circumstances.
Sources: Heather Hammer, David Finkelhor & Andrea J. Sedlak (2002). Children Abducted by Family Members: National Estimates and Characteristics. Juvenile Justice Bulletin–NCJ196466, 1-12. Order #MC17
David Finkelhor, Heather Hammer and Andrea J. Sedlak (2002). Nonfamily Abducted Children: National Estimates and Characteristics. Juvenile Justice Bulletin–NCJ196467, 1-16. Order #MC19