The Secret FBI Files (S01E04)

Title: The Hidden FBI Documents Plot: The investigation intensifies when the FBI unveils classified documents related to the enigmatic Zodiac Killer. A handwriting expert discovers a link between the Zodiac's cryptic letters and a menacing note sent from Albany, NY, nearly 3,000 miles away. Meanwhile, the team decoding the Z-340 makes a significant advancement, bringing them closer to unraveling the killer's identity.