The details of how Chris Watts callously murdered his own children after killing their pregnant mother shocked the world.
It reached a global audience when Netflix published its American Murder: The Family Next Door documentary in 2020.
But despite the gruesome details of how the 37-year-old killed his family in a bid to be with his mistress, he has attracted female attention since being locked up.
The killer dad from Colorado, USA, has been on the receiving end of saucy letters — including bikini snaps — from women who have taken a shine to him despite his barbaric crimes.
Prosecutors from the Weld County District Attorney have previously released "dozens" of letters being sent to Watts.
The American will never be freed after being convicted on a string of charges, including three first degree murders.
Watts was slapped with five life sentences plus 48 years in prison without the possibility of parole for his murders.
In 2018, he confessed to killing his wife Shannan — who was 15 weeks pregnant with their third child — after reportedly arguing about Watts wanting a divorce.
In a frighteningly candid letter to one of his admirers, cheating Watts said it took two goes to kill his daughters, with them waking up after he attempted to suffocate them with a pillow.
The oil field operator described to police how he rolled his 34-year-old wife’s body in a sheet and put it on the floor of the backseat of his truck.
He then seated his two girls — Bella, four, and Celeste, three — on the backseat, just above their mother’s dead body.
Watts then drove to an oil work site about 40 miles from his home.
He then killed his daughters at second attempt, smothering them close to where he dumped the little girls' bodies.
He shoved his daughters' bodies in a crude oil tank, while Shannan was buried in a shallow grave nearby
Watts, who did not want another child, was having an affair with a woman from work, Nichol Kessinger, and wanted to start a new life with her.
Kessinger has said she cut off all contact with her former lover.
But, now behind bars at the Dodge Correctional Institution in Wisconsin, Watts — who narrowly avoided the death penalty — has been receiving fan mail from ladies keen to get to know him better.
Some correspondents are even asking to be able to visit him in prison, with Crime Online describing the tone of some of the writing as “racy”.
Shortly after his conviction, the district attorney's office released dozens of letters sent to the man who murdered his family and unborn child.
One woman wrote: "In my heart, I know you are a great guy.
"If you do write me back I'd be the happiest girl alive, that's for sure #teamchris #chrisisinnocent #lovehim #socute."
Another sent a saucy picture of herself wearing a bikini alongside the note: "I've found myself thinking a lot about you."
The woman said she hoped the scantily-clad image would "brighten" his day.
One writer called the triple-killer her "soulmate" in a gushing handwritten letter, while another posted her note all the way from Australia.
Many serial killers have had love interests while behind bars.
A condition called hybristophilia — a sexual attraction to people who've committed gruesome crimes — is believed to be an explanation for why so many people feel attracted to inmates like Watts.
A source told the US website People: "He got a lot of letters at first. Many of them are from women who thought he was handsome and felt compassion for him.
"He had nothing better to do, so he wrote them back. And he started having pen pals. A couple of them stood out, and they've kept in contact.
"But then he gets letters from women who want to connect with him, you know, romantically.”
