Ann Miller Kontz, 35, was sentenced to 25 to 31-1/2 years in prison after her lawyer read a statement saying she felt "a deep sense of remorse and regret" for Eric Miller's death.
"I will struggle for the rest of my life with how this could have happened," the statement said.
Authorities said Kontz, who worked at GlaxoSmithKline, was having an affair with a co-worker when her husband was poisoned by arsenic, a colorless and usually tasteless poison once common in ant and rat killers.
Under a plea deal, Kontz admitted conspiring with the co-worker, Derril Willard, and pleaded guilty to second-degree murder and conspiracy to commit first-degree murder. The two had access to arsenic at their laboratory, police have said.
Miller, a researcher at the University of North Carolina at Chapel Hill, died Dec. 2, 2000. He was 30.
Less than a month before he died, he went bowling with Willard and two others and fell ill about an hour after drinking a beer he complained was bitter, according to authorities.
He was hospitalized for a week but doctors failed to diagnose the poisoning, investigators said. Two weeks later, he again became violently ill after eating a meal prepared by his wife, investigators said. This time, doctors detected high levels of arsenic in his system, but they were unable to save him.
Willard committed suicide about a month after Miller died.
Lawyers discussed a possible plea agreement for several weeks, said District Attorney Colon Willoughby, who declined to give details about the negotiations.
"We thought that this was in the family's and the community's best interest to resolve the case this way," he said.
The plea provided an abrupt end to a complicated case that included a fight over attorney-client privilege that reached the state Supreme Court.
That dispute ended with Willard's attorney revealing information implicating Kontz, which led to her indictment a few months later. In the statement, the lawyer revealed that Willard learned from Kontz that she had injected a syringe filled with an unnamed substance into Miller while he was hospitalized.
Kontz -- who remarried after Miller's death -- acknowledged in court Monday that she poisoned her husband at least twice before his death.
She and he had a daughter, Clare, who is now 5 years old.
