
This episode covers the Zodiac Killer's interactions with victims, including Kathleen Johns and Robert Salem, and the police investigation into his crimes.
Kathleen Johns, seven months pregnant, encountered a man on March 22, 1970, who tampered with her car. After he offered to help, she became terrified and escaped, later identifying him as the Zodiac Killer from a wanted poster.
Robert Salem was found murdered in his apartment with a message written in blood that referenced the Zodiac. Despite initial connections, police ruled out the Zodiac's involvement.
Detective David Tosky, a key figure in the Zodiac investigation, worked tirelessly to connect various crimes to the Zodiac, including the murder of patrolman Richard Raditic and the disappearance of nurse Donna Lass.
The episode details the Zodiac's letters to the media, including threats and claims of additional murders, while exploring the ongoing investigation and various suspects, including Arthur Lee Allen.
The episode details the Zodiac Killer's interactions with victims and ongoing police investigations into his crimes.

This episode stands out for the following:
When I get through with them, they don't need any help.The prime suspect in the Zodiac case (Part 4/4)
My god, that's the man who picked us up!The prime suspect in the Zodiac case (Part 4/4)
You get a certain feeling about things.The prime suspect in the Zodiac case (Part 4/4)
Better than getting your rocks off with a girl.The prime suspect in the Zodiac case (Part 4/4)
I'll get to him one day and I'll bring him to justice.The prime suspect in the Zodiac case (Part 4/4)
I am not afraid of the gas chamber because it will send me to paradise.The prime suspect in the Zodiac case (Part 4/4)