"The testimony of an informant, given on behalf of the [State] [City] [County] in exchange for a legal advantage or other benefit, should be subjected to careful examination in the light of other evidence in the case, and should be acted upon with great caution. You, the jury, must weigh the credibility of his or her testimony. You should not find the defendant guilty upon such testimony alone unless, after carefully considering the testimony, you are satisfied beyond a reasonable doubt of its truth."
RCW 10.56.050