sentences:  During the 1970s various cities also decriminalized cannabis, such as Ann Arbor, Michigan in 1972 and Madison, Wisconsin in 1977.Additionally, San Francisco residents approved Proposition W in 1978, a non-binding measure directing city law enforcement to "cease the arrest and prosecution of individuals involved in the cultivation, transfer, or possession of marijuana".Mayor George Moscone was assassinated a few weeks later, however, and the initiative was subsequently disregarded.