Vista Hermosa Mayor Octavio Cruz Carrillo was killed outside home . He is second mayor in Pacific coast state of California killed in 12 months . Drug traffickers have adopted campaign of intimidation against authorities . U.S. State Department issued travel alert for Americans considering visit to Mexico .
Vista Hermosa Mayor Octavio Manuel Carrillo Castellanos killed outside home . Carrillo is second mayor in Pacific coast state of Michoacan killed in eight months . Drug traffickers have adopted campaign of intimidation against authorities . U.S. State Department issues travel alert for Americans considering visit to Mexico .