Any natural or adoptive parent who, by force, threat or deception,
or without knowledge or agreement of the child's custodian, removes
that parent's child from the physical custody of any person who
has custody of the child pursuant to a court order or removes that
parent's child from the physical custody of any person in whose
custody the child has been temporarily placed by the child's
custodian, and keeps that child for a significant period, is guilty
of kidnapping. In determining whether a period of time is "significant"
for purposes of this subsection, the court must evaluate the surrounding
facts and circumstances, including but not limited to the age of the
child and the length of previous authorized visits with the offender.
In a particular case, a relatively brief period may be considered
significant.