When it finally gets going — and that would be Episode 3 — Season 2 of the Netflix series “Mindhunter” finds some resonance by delving into one of the most notorious 20th-century serial killer cases — the Atlanta child murders of 1979-81. At least 28 children, adolescents, and adults were killed.

FBI Special Agent Holden Ford (Jonathan Groff) falls into the case almost accidentally, when he checks into an Omni hotel on an assignment to interview two other serial killers, William Pierce and William Henry Hance, and is led by a desk clerk (Sierra McClain) to three mothers whose children have disappeared. The pain and frustration conveyed by these women persuade him to find a way into the case, which occurs with a kidnapping that crosses state lines. The scenes give the usually bland Groff a chance to stand out, and it will be interesting to see how the series handles issues of crime and race as it traces the FBI’s involvement in the remaining six episodes.

“Mindhunter” juggles several cases at once as the Behavioral Science Unit (BSU) is dispatched to various prisons around the United States to gather into about killers at large. Ford and Bill Tench (Holt McCallany) go to Attica to talk to David Berkowitz (Oliver Cooper) to get insights into the BTK (Bind, Torture, Kill) strangler, Dennis Rader (Sonny Valicenti), who remained at large in the late 1970s (he was captured in 2005). When Berkowitz sees that BTK has fashioned a symbol for himself modeled on the one that Son of Sam created, he dismisses him. “It’s a total ripoff,” he says.

An unexpected twist in a case in Tench’s Virginia neighborhood strikes close to home for the special agent and “Mindhunter” takes on extra personal dimension, always helpful in a procedural.

‘Mindhunter’ is a series for people who live for true-crime stories, serial killer sitdowns and the grisly monologues.

McCallany is particularly good at showing how one man in his position manages to keep his family’s anxieties at bay while managing his superiors’ expectations at work.

The other member of the BSU team, the circumspect Dr. Wendy Carr (“Fringe” veteran Anna Torv), is only a consultant but Torv shines in a couple of scenes where she does her first interview with a protege of serial killer Dean Corll, offering up a risky bit of personal backstory as a way to draw him out, and goes out on a bowling date with Kay (Lauren Glazier), a sexy bartender she meets while on the job.

While the series benefits from giving everyone more to do, the pacing could be quicker. After two years off the air, one would have thought director David Fincher would get down to business right away. Episode 1 takes too long to tell us about changes in the FBI administration (Cotter Smith is out, Broadway veteran Michael Cerveris is in as the boss) and show us new office space.

“Mindhunter” is a series for people who live for true-crime stories, serial killer sitdowns and the grisly monologues that mankind’s monsters deliver with panache as they tell us how they polished off their victims. Give the people what they want, Mr. Fincher.

With three programs/films available on the ID network or Netflix on Ted Bundy in one year, our fascination with multiple murderers runs deep and “Mindhunters” should expand its fan base by upcoming scenes with Charles Manson (Damon Herriman, “Perpetual Grace, Ltd.”), a figure so popular he’s been on TV shows and films since the CBS TV movie “Helter Skelter” in 1976.