This is the zodiac speaking is a three-part documentary directed by Ari Mark and Phil Lott that examines how Arthur Leigh Allen, long suspected of being the infamous Zodiac Killer, terrorized the San Francisco Bay Area in the late 1960s and early 1970s. The Zodiac Killer had five known victims, but letters he sent to San Francisco newspapers, complete with coded messages that were only partially broken, claimed he killed dozens. But the Seawater family knew him as a teacher and family friend.

Opening shot: Scenes of an empty community pool and complex and people from the Seawater family talking about how graceful a diver Arthur Leigh Allen was, especially for a tall man.

The essentials: The series moves back and forth between the early 1960s, with interviews with the various Seawater siblings who had Allen as a teacher when they were in elementary school, and the late 1960s, when the murder of a young couple occurred The first of the zodiac signs was pursued in Vallejo.

Because Allen helped the Seawater's mother, who raised the family alone, the siblings found some of Allen's behavior not so strange, especially when it came to how he acted around young girls. One of the siblings says that he was later told that he would care for her, but that term didn't even exist back then.

Back in 1969, the Zodiac Killer taunts the newspapers and the police with his letters, complete with a crosshair-like symbol at the end. He shoots some people and stabs others. He threatens to kill children on a school bus. Robert Graysmith, a San Francisco Chronicle The cartoonist who became one of the reporters who followed the case is interviewed, and over 50 years later, the idea that the Zodiac Killer would shoot up a school bus still haunts him deeply. He documents some of the near misses that law enforcement experienced in arresting Allen after some of the murders. He was also one of the people who began to suspect that Allen was the Zodiac Killer, but had no hard evidence linking him to the murders.

What shows will it remind you of? Mastermind: Think like a killer, Creating a murderer, The curse, Conversations with a murderer…there is no shortage of documentaries about serial killers, including numerous documentaries and series about the Zodiac Killer. There's also David Fincher's 2007 true-crime epic, Zodiacwhich focuses more on Graysmith's pursuit of the story than the murderer himself.

Our opinion: What does This is the zodiac speaking What's different from other documentaries about serial killers in general and Zodiac in particular is that Mark and Lott take the perspective of a family who knew the alleged murderer in a very different context. Even more than sixty years after Allen was in the lives of the Seawater family, the children who were often in his company and under his care have fond memories of him, knowing what they know about him now.

We're not usually a fan of documentaries that jump back and forth on a story's timeline, but the narrative method is useful here, especially to serve as contrast and fill in some gaps about murders that Allen likely committed before the Zodiac's flood Murders Committed was released in Northern California in late 1968. Considering how the Seawaters spoke about him, the contrast between the strange man who played folk music and the songs of The Mikado in class and was a graceful diver and swimmer and the man who wrote this letter was sober.

Since the murders occurred more than five decades ago, the interviews seem to have a “now or never” feel, considering the Seawaters are all in their 70s, Graysmith is in his 80s, and friends of some of his early and late Victims are also in this age group. Her memory of her views on Allen is as clear to her as it was decades ago, which, combined with low-key reenactments, archival news footage, photos and home videos of Allen, paints a dynamic picture of a man who doesn't fit the usual serial killer stereotype.

Gender and skin: None.

Parting shot: The Seawaters describe an incident in which Allen took them to a beach, hurriedly put something in the back seat of their car and sped off. It was probably related to two murders that were later linked to him.

Sleeperstar: Remarkable is Graysmith's recollection of what he did 55 years ago to report on the Zodiac's activity.

Most Pilot-y Lines: We couldn't find any.

Our call: STREAM IT. This is the zodiac speaking gives a new perspective on a serial killer story that is decades old but has never been fully solved.

Joel Keller (@joelkeller) writes about food, entertainment, parenting and technology, but he's not kidding himself: He's a TV junkie. His writing has appeared in The New York Times, Slate, Salon, RollingStone.com, VanityFair.comFast Company and elsewhere.