SPOILER ALERT!
If you’re planning to watch Zodiac, save this read for af ter…
On 1 August 1969, a letter arrived at the offices of the San Francisco Chronicle.
In it, a killer boasted he’d murdered three teenagers in northern California.
The first were Betty Lou Jensen, 16, and David Faraday, 17. The couple had been huddled in a car near Lake Herman at 11.15pm on 20 December 1968, when the car was peppered with bullets.
Then, in July 1969, Darlene Ferrin, 22, and Michael Mageau, 19, were parked in the Blue Rock Springs Golf Course, Vallejo.
The killer pulled up, got out of the car and opened fire.
Michael survived, describing the attacker as 5ft 8in, heavy-set.
Almost identical letters had been sent to two other local newspapers.
To…