There were so many disastrous coincidences in the life of Karl Karlsen that even his second wife thought it sounded unbelievable.

The first happened on New Year’s Day in 1991, in his home, a former gold miner’s shack in the foothills of the Sierra Nevada mountains. That day, Karlsen’s first wife, 30-year-old Christina, died in a fire while trapped in a bathroom behind a boarded-up window.

The fire itself was the result of a series of incredible coincidental accidents, Karlsen would soon tell investigators. The bathroom window was boarded up because Christina had accidentally broken it three days earlier, Karlsen told them, according to a report in the Syracuse Post-Standard. A jug of kerosene was in the hallway outside the bathroom, put there accidentally by Christina, who thought it was a jug of water, he claimed. The jug had been accidentally spilled onto the hallway carpet by a cat and dog, he told investigators.

And Karlsen had accidentally placed a defective electric light too close to the kerosene-soaked carpet, igniting the blaze.

Firefighters ruled the fire accidental.

Karlsen collected $200,000 in life insurance that he had taken out on Christina just 20 days before her death, according to a court document. He then moved to New York.

“The way he explained it made perfect sense to me,” his second wife, Cindy Best, said of Christina’s tragic death, speaking to the Post-Standard years later. “Karl had an answer for everything.”

In late 2008, nearly 18 years after the fire, Karlsen’s 23-year-old son, Levi, died in yet another alleged freak accident, coincidentally on the same day Levi signed a will that left his entire estate to Karlsen. He had crushed his son beneath a pickup truck, leaving him to die under its weight, and then collected $707,000 from Levi’s life insurance, according to court filings by Seneca County, N.Y., prosecutors.

Now, Cindy had to ask the question: Could this really have been another coincidence?

Cindy brought her concerns to police, saying she feared Levi’s death was not just another accident. Police began an investigation — and in 2013, that investigation led to Karlsen pleading guilty to second-degree murder in Levi’s 2008 death.

It also led California authorities to take a second look at the 1991 death of Christina Karlsen.

And on Monday, a California jury returned a verdict: That wasn’t an accident either.

Nearly three decades after the fatal fire, the Calaveras County, Calif., jury convicted Karlsen of first-degree murder by arson in Christina’s death, finding that he killed her “for financial gain” before moving to New York and killing his son by concocting a similar scheme.

Karlsen’s daughter, 36-year-old Erin DeRoche, told the jury last month that she visited her father in jail as he awaited trial in Levi’s death, the Union Democrat reported. She told him she had made up her mind about what he had done.

“I told him I knew he killed my mother and brother,” she testified, according to the Union Democrat. “He grinned like a Cheshire cat and said, ‘It’s been 20 years. They haven’t caught me yet, they’re not going to.’”

Karlsen’s defense attorney, Richard Esquivel, told The Washington Post Thursday morning that he is planning to appeal.

“This prosecution was a knee-jerk reaction to the death of Mr. Karlsen’s son in New York,” Esquivel said. “Aside from his death, there was no new evidence the DA’s office could point to to justify Mr. Karlsen’s prosecution. They relied on the same evidence they were shown and rejected 29 years ago.”

In 1991, Karlsen moved the children to Varick, N.Y., his hometown, within a few days after Christina’s death, before she had even been buried. Investigators in California found the amount of coincidences that led to the fatal fire to be “incredible,” as one told the Post-Standard in 2012, but once Karlsen left town, the investigation ended.

Settling down in Varick, Karlsen married Cindy in 1993, had another child with her and lived quietly on a farm — until the second freak incident in 2008.

That November, Karlsen went with Levi to take out a $700,000 life insurance police on Levi’s life, naming himself as the sole beneficiary. A little over two weeks later, the father and son also went to a notary public so that Levi could sign a handwritten will, giving his father his entire estate, according to Seneca County court documents.

Karlsen then asked Levi if he wouldn’t mind doing some work on a farm truck back at the house. Levi agreed.

Just hours later, the 23-year-old man, a father of two, laid on his back underneath the truck to take a look. It was propped up on a wobbly jack. The front wheels had been removed, and there were no safety blocks supporting the vehicle in the event that the jack broke and the truck fell.

Knowing this, Karlsen hopped into the truck’s front cab — causing the front-end of the truck to collapse onto his son’s body, according to Karlsen’s own admission in plea documents. As Levi writhed in agony, Karlsen turned up the volume on the radio, masking his son’s screams.

And then he left.

He went to a funeral with Cindy and returned four hours later. He feigned shock at discovering his dead son underneath the truck, frantically calling for Cindy to dial 911, according to court documents.

On the way to the hospital, Karlsen’s sister-in-law, Jackie Karlsen, remembered, “He said he couldn’t believe how one person could have so much bad luck in his life,” she said during testimony, the Union Democrat reported.

Cindy told the Post-Standard that she started having panic attacks in the years after Levi’s death. The coincidences started getting to her. She eventually decided to hire a private detective to investigate how Karlsen was spending the $700,000 in life insurance.

She learned he had invested some of it into a life insurance policy on her own life — and that, again, he named himself as the sole beneficiary, according to Seneca County court documents.

“I found out it was actually a life policy on me, and I would be worth $1.2 million dead to Karl,” she testified in a court hearing, the Post-Standard reported in 2013.

Fearing Karlsen may be planning to kill her, she took her their son, Alexander, and fled to Kentucky to live with a cousin. She alerted police, prosecutors wrote, and started recording their conversations. Over lunch in November 2012, Cindy, by then estranged from Karlsen, demanded that he tell her the truth about how Levi died.

He ultimately confessed — and was soon charged with depraved-indifference murder in the second degree.

Karlsen would later plead guilty on the same day his trial was scheduled to begin in 2013, but insisted on his innocence up until that moment. In a jailhouse interview with the Post-Standard as he awaited trial, Karlsen blamed his arrest on a vindictive wife, saying how unusual it was that she came forward to the police in the middle of their divorce.

“What a coincidence, don’t you think?” he said.