You may claim a kidnapped child as your dependent if the following requirements
The child must be presumed by law enforcement to have been kidnapped by
someone who is not a member of your family or a member of the child's family,
The child must have qualified as your dependent for part of the tax year
before the kidnapping.
If both of these requirements are met, the child is treated as your
dependent for the following purposes:
The dependency exemption
The child tax credit, and
Head of household or qualifying widow(er) with dependent child filing
If the first requirement is met and if the child lived with you for more
than half of the year before the date of the kidnapping, the child is treated
as living with you for more than half of the year for purposes of the earned
This tax treatment will cease to apply as of your first tax year beginning
after the calendar year in which either there is a determination that the
child is dead or the child would have reached age 18, whichever occurs first.
For more information, refer to Publication 501, Exemptions, Standard
Deduction, and Filing Information.