(a) Offense defined.--Except as provided under subsection (b) or (c), a person commits a misdemeanor of the second degree if he knowingly restrains another unlawfully so as to interfere substantially with his liberty.
(b) False imprisonment of a minor where offender is not victim's parent.--If the victim is a person under 18 years of age, a person who is not the victim's parent commits a felony of the second degree if he knowingly restrains another unlawfully so as to interfere substantially with his liberty.
(c) False imprisonment of a minor where offender is victim's parent.--If the victim is a person under 18 years of age, a parent of the victim commits a felony of the second degree if he knowingly restrains another unlawfully so as to interfere substantially with his liberty.
(d) Definition.--As used in this section the term "parent" means a natural parent, stepparent, adoptive parent or guardian of a minor.