Wash. Rev. Code § 9.45.260
Any fire protection sprinkler system contractor, defined under RCW 18.160.010, who willfully and maliciously constructs, installs, or maintains a fire protection sprinkler system in any structure so as to threaten the safety of any occupant or user of the structure in the event of a fire, is guilty of a class C felony. This section may not be construed to create any criminal liability for a prime contractor or an owner of a structure unless it is proved that the prime contractor or owner had actual knowledge of an illegal construction, installation, or maintenance of a fire protection sprinkler system by a fire protection sprinkler system contractor.
RCW 9.45.260
Fire protection sprinkler system contractors, licensing and regulation: Chapter 18.160 RCW.