Officer William M. Freeman, a 32-year-old California Highway Patrol officer, was killed on December 22, 1978, during a routine traffic stop on Interstate 80 near the Yolo Causeway in West Sacramento. Freeman and his partner, Officer Roy P. Blecher, were involved in a violent confrontation after the stop; signs of a struggle were found at the scene. Blecher was discovered handcuffed with a fatal gunshot wound to the back of his head, and Freeman had been overpowered and shot five times. Their last radio contact was at 3:12 a.m., shortly before the attack.

A suspect, 23-year-old Luis Valenzuela Rodriguez, was apprehended a few days later on Christmas Eve, along with his 18-year-old girlfriend, Margaret Klaess. Klaess remained in the car during the incident, later turned state’s evidence, testified against Rodriguez as part of a plea agreement, and served two years in prison for aiding and abetting. Rodriguez was tried in a seven-month trial; he was initially sentenced to death, his sentence was later commuted to life without the possibility of parole in 1991, and he died of natural causes on April 16, 2016. The Yolo Causeway was renamed the Blecher-Freeman Memorial Causeway in 1994.