Mo. Rev. Stat. § 577.612: Tampering with or circumventing the operation of an interlock device — penalty.

1. A person commits the offense of tampering with or circumventing the operation of an ignition interlock device if:

(1) His or her driving privilege is restricted by a prohibition on the operation of any vehicle unless that vehicle is equipped with a functioning, certified ignition interlock device, and he or she knowingly requests or solicits any other person to blow into an ignition interlock device or to start a vehicle equipped with the device for the purpose of providing the person so restricted with an operable vehicle; or

(2) He or she blows into an ignition interlock device or starts a vehicle equipped with the device for the purpose of providing an operable vehicle to a person whose driving privilege is restricted pursuant to the provisions of this chapter or chapter 302 by a prohibition on the operation of any vehicle unless that vehicle is equipped with a functioning, certified ignition interlock device; or

(3) He or she tampers with, or circumvents the operation of, an ignition interlock device.

2. The offense of tampering with or circumventing the operation of an ignition interlock device is a class A misdemeanor.