Mo. Rev. Stat. § 568.030: Abandonment of child in the first degree, penalty.

1. A person commits the offense of abandonment of a child in the first degree if, as a parent, guardian or other person legally charged with the care or custody of a child less than four years of age, he or she leaves the child in any place with purpose wholly to abandon the child, under circumstances which are likely to result in serious physical injury or death.

2. The offense of abandonment of a child in the first degree is a class B felony, unless the child dies, in which case it is a class A felony.