(1) Any person required to register under the Sex Offender Registration Act who violates the act is guilty of a Class IIIA felony.

(2) Any person required to register under the act who violates the act and who has previously been convicted of a violation of the act is guilty of a Class IIA felony and shall be sentenced to a mandatory minimum term of at least one year in prison unless the violation which caused the person to be placed on the registry was a misdemeanor, in which case the violation of the act shall be a Class IIIA felony.

(3) Any law enforcement agency with jurisdiction in the area in which a person required to register under the act resides, has a temporary domicile, maintains a habitual living location, is employed, carries on a vocation, or attends school shall investigate and enforce violations of the act.