Wash. Rev. Code § 10.122.090
A custodial interrogation to which RCW 10.122.030 otherwise applies need not be recorded electronically if a law enforcement officer conducting the interrogation or the officer's superior reasonably believes that electronic recording would disclose the identity of a confidential informant or jeopardize the safety of an officer, the individual being interrogated, or another individual. If feasible and consistent with the safety of a confidential informant, an explanation of the basis for the belief that electronic recording would disclose the informant's identity must be recorded electronically at the time of the interrogation. If contemporaneous recording of the basis for the belief is not feasible, the recording must be made as soon as practicable after the interrogation is completed.
RCW 10.122.090