Obsession can take many forms, and a few are on display in The Sons of Sam: A Descent Into Darkness, the latest Netflix docuseries. In 1977, there was a great reign of terror in New York City due to the “.44 Killer,” later known as the “Son of Sam.” Fear was pervasive, and the shootings that actually started in the summer of 1976 but not connected until months later, mostly seemed random, which added to the public panic. Despite the title, the docuseries is not so much about the murders, but about one man’s obsession with proving the “Son of Sam” was really more than one person, and that the relief felt by citizens after the arrest of David Berkowitz, was misplaced.

Maury Terry was an IBM employee with an exceedingly inquisitive mind. His interest in the Son of Sam case pushed him to slowly evolve into an investigative journalist. He became ultimately convinced that the NYPD had closed the case too soon, and not approached his own level of in-depth research and detail. Director Joshua Zeman brings all of Terry’s obsessive research into four episodes. Paul Giamatti reads Terry’s own notes and book passages, and Zeman fills the four episodes with archival news clips, Terry’s own videos, shots of newspaper clippings, and interviews (past and present) from family members, cops, journalists, and even surviving victims.

Towards the end of the first episode, we see the iconic video of David Berkowitz smiling at the camera as police take him into custody. Since a rare .44 caliber pistol was found with him, and Berkowitz confessed to the murders during his interrogation, the NYPD was quick to go on TV and announce to a relieved citizenry that the streets of New York were again safe, and Son of Sam was behind bars.

However, for Terry, the case and the evidence just didn’t add up. He was intrigued by many bits and pieces. Berkowitz stated that his actions had been guided by a 1,000-year-old demon through his neighbor’s dog. Additionally, the variances in police sketches drawn from eyewitnesses over the year simply didn’t add up to be the same guy. As to Berkowitz himself, the personality of the Yonkers postal worker didn’t fit cleanly into the police profile either. The more skeptical Terry became, the more doubt his research created. The final 3 episodes really focus on the casework he performed over decades especially his belief that the murders traced back to a satanic cult.

Even more than 40 years later, the events prove traumatic to revisit and are only made creepier by Terry’s theories. Was he on the right path or was he a lunatic conspiracy theorist, as many described? It’s only now that we can question the accuracy of Berkowitz’s first letter to Terry when he told him, “The public will never truly believe you.” Whether accurate or not, there is no questioning Maury Terry’s obsession with the Son of Sam case. Zeman’s docuseries will leave you wondering what’s real.