The Revised Code of Washington 46.52.065 requires that “a blood sample be taken from all drivers and all pedestrians who are killed in any traffic [crash] where the death occurred within four hours” for analysis by the state toxicologist “to determine the concentration of alcohol and, where feasible, the presence of drugs or other toxic substances.” This statute has led to statewide testing rates for deceased drivers of almost 90 percent.
In investigations of fatal or serious car accidents where potential at fault parties are not fatally injured they are still require to submit to testing due to the states "Implied Consent" law. This means that if a driver is unresponsive or even unconscious, but alive, authorities are not required to get consent before ordering a test.