Joshua Niles was gunned down in the prime of his life while his wife, Amber Washburn, and young son watched from a nearby vehicle on October 22, 2018. Then, the gunman fired once at Washburn, killing her, before disappearing.

Niles and Washburn's murders were the final steps in a child-custody plot gone too far, according to “Killer Couples” on Oxygen.

Niles, 28, had two young children with Charlene Childers, 25 at the time of the murder. The two were high-school sweethearts who grew up in Sodus, New York. They had moved in together and had their first child at a young age and were soon married. Things didn't work out, however: Niles and Childers made two beautiful children, but just weren't compatible, his mother, Barb Niles, told the Rochester Democrat & Chronicle.

Charlene Childers

After a separation, Childers moved to Sunray, Texas, in 2013. The two remained cordial, with the children back and forth between Texas and New York for holidays, even after Childers remarried in 2014, a marriage that lasted until 2018. She had been carrying on an affair with the Sunray chief of police, Tim Dean, according to “Killer Couples,” when she filed for divorce. Dean and Childers married about a month later.

Their relationship, however, also entered troubled waters when Dean was hit with child abuse charges in May 2018. He lost his job with the police department, and when Niles — who was now married to Washburn — caught wind of the situation, he filed for full custody of his and Childers' two children. Childers was infuriated and visited Sodus several times to try to change Niles’ mind, according to “Killer Couples.”

In October, sheriff's deputies responded to Niles and Washburn's Sodus home on reports of a shooting. Niles had been exchanging words with a man in his driveway who then pulled a handgun and shot him down. Washburn was just pulling into the driveway at the time of the killing, with her youngest son in the back of the car. As she tried to reverse her way to safety, the gunman shot her dead, then finished Niles off by emptying the gun into him as he tried to crawl underneath his truck.

It didn't take authorities long to connect the killings to Niles and Childers' ongoing custody dispute. When they called Childers on her cell, she was already on her way to New York to collect her kids, according to “Killer Couples.”

Childers was questioned by detectives and insisted she knew nothing beyond news reports and, despite the custody battle, that she would never hurt Niles or his wife.

“That's still the father of my damn kids,” she tells police in interview footage featured on the episode. “And the woman who stepped up and was a great mom to my kids is gone, too!”

Authorities kept Childers in custody while they tracked down Dean. In the meantime, they learned that Dean had missed several shifts recently at his new job — including on the day of the murders. Dean also had been involved in a rental car wreck somewhere in Kansas two days before the murders. Amplifying their suspicion, detectives viewed body-camera footage from officers responding to the accident.

Dean had several firearms in the car and complained to officers that his life had “kind of gone to s—t lately,” and was evasive when it came to explaining the small arsenal. On the footage, he told police that he was going to visit a “family friend” in New York. They also found that someone else had rented the car for Dean: His old co-worker Bron Bohlar's name was on the rental.

Authorities pressed Bohlar until he confessed that he had rented the car for Dean as a favor, and that his friend had at least discussed taking it up to New York to kill his wife's ex. Bohlar also said that Childers was there when he and Dean discussed the plan.

Bohlar was charged with conspiracy, and Dean was charged with murder. Authorities in Texas cooperated with Sodus sheriff's deputies and executed a “high-risk” arrest of Dean at his home in Sunray, according to “Killer Couples.” After about an hour of negotiation and one flashbang lobbed inside the house, Dean surrendered.

He never confessed to the murder, but Bohlar's statement and an eyewitness in Sodus who positively ID'd Dean as the shooter based on a photograph were enough to charge him. Authorities were able to charge Childers after she finally admitted to discussing the murder of her ex with Dean.

She claimed that Niles was constantly bad-mouthing her.

“I was like, 'God, I wish he would just f--king die in a ditch somewhere,” she tells police in interview footage seen on “Killer Couples,” eventually admitting that she told Dean, “F--king shoot him. Just shoot him.”

Tim Dean

In May 2019, Dean went to trial, with Childers as the star witness. Barb Niles told “Killer Couples” that her late son's ex was often smiling when she walked into the courtroom, and admitted that she sometimes wanted to “knock her teeth in.”

Dean was convicted and sentenced to life without parole. Childers accepted a plea deal, downgrading her charge to first-degree manslaughter; she was given 28 years and will be eligible for parole when she's 49.

For more on the double-murder of Josh Niles and Amber Washburn, watch “Killer Couples” at Oxygen.com and airing Thursdays at 8/7c.