In 2004, the serial killer known as BTK—a stand-in for his modus operandi of “bind, torture, kill”—mailed a letter to a newsroom in Wichita, Kansas, taking credit for the decades-old unsolved murder of Vicki Wegerle, a 28-year old local who had been found strangled to death in 1986. The letter was the first anyone had heard from BTK in nearly 25 years since he stopped communications with the police and news media in 1979—but it was that letter, police say, that led to his capture one year later in 2005.

BTK's capture stunned the nation: Although FBI profilers had theorized that the killer—revealed to be Dennis Rader—was a loner, Rader was actually a married, 59-year-old veteran and compliance officer, as well as president of his church council and a former Boy Scout Leader. Rader was also a husband and father of two, who by their account was “kind” and “warm.” His daughter, Kerri Rawson, has written about her experiences as Rader's daughter, maintaining that she and her family knew nothing about her father's double life until his arrest.

Studying serial killers is a relatively new science, so what we know about them as a group is limited. However, according to a 2005 report from the FBI, serial murderers are often not the dysfunctional loners typically portrayed in pop culture. Instead, the report says, serial killers “often have families and homes, are gainfully employed, and appear to be normal members of the community.” One such example is Robert Yates, a serial killer who had five children and was a decorated member of the National Guard; another is Gary Ridgeway—better known as the Green River Killer—who had a wife and son.

And as little as we know about serial killers, we know even less about their immediate families, says Dr. Andrew Mendonsa, a forensic and clinical psychologist based in California. “There's no research that I know of, as for how a serial killer's [immediate] family turns out in the long run,” he says. A new drama series from FOX, however, attempts to show what that might look like. “Prodigal Son” follows a gifted, idiosyncratic (and fictional) psychologist Malcolm Bright (Tom Payne), who reluctantly reconnects with his infamous serial killer father (Michael Sheen) for direct insight into the psyches of killers while working with the NYPD.

Based on Mendonsa's anecdotal experiences, immediate families tend to disengage from the serial killer in the aftermath of his capture. “I've had to interview serial killers through my work, and you don't often see a family connection beyond maybe an extended grandmother,” Mendonsa says. “You very rarely see the wife and kids involved afterward.” Families also tend to disengage from the community as well. “I live in the town where the Golden State Killer was found,” Mendonsa says. “His wife was well-respected in the community and so were the kids, and they've all gone dark. People tend to go underground when that happens because there's a lot of shame involved.”

In an effort to understand serial killer psychopathy, some researchers have wondered whether being raised by a serial killer makes one more likely to murder or become serial killers themselves. In “Prodigal Son,” Malcolm Bright leverages his experiences with his father as an opportunity to help the NYPD—but his actions call into question whether or not Bright might be a psychopath himself.

“ Serial killers are as individualistic among their peers as the rest of us are, as a society. ” — Dr. Robert Schug

What causes a serial killer is a complicated interplay of nature and nurture, says Dr. Robert Schug, a neurocriminologist and professor in the department of criminal justice at California State University, Long Beach.

“Serial killers are as individualistic among their peers as the rest of us are, as a society,” says Schug. “What we do know about violence and murder in general is that it's typically not just one thing that goes wrong—it's a perfect storm of things that go wrong for many years.” Researchers know that some risk factors can result in the formation of a serial killer—environmental factors like abuse, neglect, brain injury, and parental discord—but as for biology? “It's just a big fat maybe,” says Schug.

Still, it can't be completely ruled out: In December 1989, 27-year-old Jeffrey Landrigan stabbed a man named Chester Dean Dyer to death in Phoenix, AZ. During his subsequent prison sentence, Landrigan discovered that his biological father, whom he had never met, had also been on death row for murder in Arkansas. Like his biological father, Landrigan had escaped from prison at one point during his sentence.

“What it seems to come down to is a mixture of genetics for violence mixed with early childhood experiences of learning to be extremely violent,” says Schug, who describes the Landrigan murder as “just one data point” in our understanding of how biology influences crime.

“ It's worth taking a step back and acknowledging that all successful people have characteristics of psychopathy, and it's not just reserved for serial killers. ” — Dr. Andrew Mendonsa

As for family influence, it could be that one person's psychopathy is another family member's success. Malcolm Bright, for instance, is able to think like a serial killer and even exhibits some “psychotic inclinations” similar to his father, such as extreme attention to detail and a tendency toward narcissism. But rather than channeling those inclinations into killing, Bright uses them to advance his career.

“When we're discussing serial killers, it's worth taking a step back and acknowledging that all successful people have characteristics of psychopathy, and it's not just reserved for serial killers,” Mendonsa explains. Successful people who demonstrate “psychopathic” traits like cunningness or a desire for control sometimes end up as CEOs—or, in Malcolm Bright's case, as criminal psychologists—because they're able to use those traits in socially acceptable ways, rather than mass murder. “People are able to use this psychological construct differently—it doesn't necessarily consume them,” he says.

But while there's no conclusive evidence to support the notion that serial killers breed other serial killers, it's also not outside the realm of possibility, says Mendonsa. “Psychologically, what it does to kids and juveniles whose parents have ended up in the prison system, is that they feel like there's this devaluation of their opportunities in the world,” he says.

Like Bright, the stigma of having a notorious family member can follow them to school, in their adult life, and beyond. And, Mendonsa says, the stigma and shame that comes with having a family member as a criminal can have a “very detrimental effect,” particularly if the child is very young and families don't have the right resources to deal with their trauma. Also like Bright, children who are forced to deal with their parent's incarceration, as well as coming to terms with their identity as serial killers, might also suffer from complex post-traumatic stress, nightmares or sleep terrors, and nervous tics.

“It's important to have good interventions for children with risk factors,” Mendonsa says. “Without them, you maybe could be setting the groundwork for them to be the next big serial killer.”

Looking to dive deeper into the complex perspectives and relationships born out of having a serial killer in the family? Tune in to “Prodigal Son,” a new twisted family drama premiering Monday, September 23 at 9/8c only on FOX.