An Orange County woman claims that her father, Guy Ward Hendrickson, was the infamous Zodiac Killer, who terrorized the Bay Area in the late 1960s and whose identity has remained a mystery to investigators.

Deborah Perez said that as a 7-year-old, she accompanied her father to two killings – one in Vallejo and one in San Francisco. Perez, who is now taking part in a documentary about the crime spree, said she wrote some of the killer’s letters. Her father died in 1983 and was mentally ill, she said.