After a spellbinding five-day trial that featured tales of infidelity and a multimillion dollar insurance payout, a jury on Friday convicted a Florida woman of helping mastermind the killing of her husband nearly two decades ago.

Jurors found Denise Williams guilty of three counts including first-degree murder and conspiracy to commit murder for her role in a case that has recalled the plot of the Hollywood film classic "Double Indemnity." The 48-year-old Williams was found guilty after testimony by a key witness, the man who shot her husband Mike Williams on a cold December morning on a large lake west of Tallahassee.

Jurors deliberated eight hours before reaching a verdict. Denise Williams, who could spend the rest of her life in prison, is to be sentenced at an unspecified date next year.

Mike Williams disappeared nearly 18 years ago to the date of his wife's conviction. He left early on the morning of Dec. 16, 2000, to go duck hunting, and initially some speculated he had fallen from his boat and that his body had been devoured by alligators. His disappearance triggered a massive search by authorities.

But Brian Winchester, who had been Mike Williams's best friend, said he and Denise Williams were having an affair and that they planned the killing. Denise Williams ultimately received $1.75 million in life insurance payments, including a $1 million policy that Winchester himself had sold Mike Williams.

In the film "Double Indemnity," an insurance agent helps his lover kill her husband in order to cash in on a life insurance policy.

Winchester said he planned to make it look like Williams had drowned. But after pushing him overboard, Williams did not get dragged underwater by his duck-hunting equipment. So Winchester said he shot him in the face with a 12-gauge shotgun. He then dragged his body to shore, put him in the back of his truck and drove back to Tallahassee. He eventually buried him later in the day alongside a small lake located north of town.

Without a body, Denise Williams petitioned to have her husband declared dead due to accidental drowning. Winchester and Denise Williams married in 2005 but the relationship soured and they divorced in 2016.

The case broke after Winchester kidnapped his ex-wife at gunpoint in 2016, authorities said. He eventually made a deal with prosecutors and was sentenced to 20 years in prison for that crime. But Winchester ultimately led authorities to the remains of Mike Williams.

Ethan Way, an attorney for Denise Williams, told jurors during closing statements that his client was innocent and that there was no tangible proof that Denise Williams helped plan the slaying of Mike Williams. Instead he maintained that Winchester was lying in order to avoid murder charges and get revenge on his ex-wife.

"They gave a free pass to a murderer and got nothing else," Way told jurors in his closing statement.

State Attorney Jon Fuchs told jurors it "turns my stomach" that prosecutors gave Winchester immunity in the case, but he said it was important to give "closure" to other members of the Williams family who had suspected for years that Mike Williams did not drown. Fuchs said that Winchester would still be in prison for a long time.

Right before he ended, Fuchs took something out of his pocket and placed it before the jury: It was the wedding band that Mike Williams was wearing the day he died.

Some friends and relatives of Mike Williams sobbed quietly after the verdict and louder yet after the jury left the courtroom. Cheryl Williams, the mother of Mike Williams, thanked prosecutors for their work on the case.

"I am just happy we were able to do our job as a team and bring justice to Mike and his family," Fuchs said afterward. He added "it's not every day in your career that you get to be involved in an unsolved homicide that's 17 years old and through team effort able to make an arrest and ultimately get a conviction."

Way said his client Denise Williams was "stunned" by the verdict and he vowed to appeal it.

"It's terrible, it's the wrong verdict on the facts," Way said. "But I think you have to respect what the jury does. Obviously I don't believe she's guilty of any of the three counts, I don't think anyone on the defense team does."