The University of Washington is authorized and directed to arrange for a drug testing laboratory. The laboratory shall offer a testing service for law enforcement officers for the identification of known or suspected dangerous and narcotic drugs. Employees of the laboratory are authorized to appear as expert witnesses in criminal trials held within the state: PROVIDED, That the traveling expenses and per diem of such employees shall be borne by the party for the benefit of whom the testimony of such employees is requested.
RCW 28B.20.315