(1) If a law enforcement agency receives a complaint that alleges that a child under age twelve has committed a sex offense as defined in RCW 9.94A.030, the agency shall investigate the complaint. If the investigation reveals that probable cause exists to believe that the youth may have committed a sex offense and the child is at least eight years of age, the agency shall refer the case to the proper county prosecuting attorney for appropriate action to determine whether the child may be prosecuted or is a sexually aggressive youth. If the child is less than eight years old, the law enforcement agency shall refer the case to the department.

(2) If the prosecutor or a judge determines the child cannot be prosecuted for the alleged sex offense because the child is incapable of committing a crime as provided in RCW 9A.04.050 and the prosecutor believes that probable cause exists to believe that the child engaged in acts that would constitute a sex offense, the prosecutor shall refer the child as a sexually aggressive youth to the department. The prosecutor shall provide the department with an affidavit stating that the prosecutor has determined that probable cause exists to believe that the juvenile has committed acts that could be prosecuted as a sex offense but the case is not being prosecuted because the juvenile is incapable of committing a crime as provided in RCW 9A.04.050.

(3) The department shall investigate any referrals that allege that a child is a sexually aggressive youth. The purpose of the investigation shall be to determine whether the child is abused or neglected, as defined in this chapter, and whether the child or the child's parents are in need of services or treatment. The department may offer appropriate available services and treatment to a sexually aggressive youth and his or her parents or legal guardians as provided in RCW 74.13.075 and may refer the child and his or her parents to appropriate treatment and services available within the community. If the parents refuse to accept or fail to obtain appropriate treatment or services under circumstances that indicate that the refusal or failure is child abuse or neglect, as defined in this chapter, the department may pursue a dependency action as provided in chapter 13.34 RCW.

(4) Nothing in this section shall affect the responsibility of a law enforcement agency to report incidents of abuse or neglect as required in RCW 26.44.030(5).