Brian Scott Card was 19 when he was killed on February 10, 1973, while camping with three other teenagers in Henry Cowell Redwoods State Park. The four — Brian, David Allan Oliker, Robert Michael Spector and Mark John Dreibelbis — were approached by Herbert Mullin, who posed as a park ranger and told them to leave because they were polluting the forest. When they refused, Mullin returned the next day and shot them to death; their bodies were found a week later.

Investigators matched bullets recovered from the victims to weapons seized from Mullin’s car. Mullin was arrested soon after the killings, charged with multiple counts of murder, and ultimately convicted and sentenced to life imprisonment; his actions were linked to delusions that murdering people would prevent earthquakes, and his history of mental instability and drug use, including LSD, was noted in the case.