The woman who in 2006 falsely accused three Duke university lacrosse players of raping her has been convicted of stabbing her boyfriend to death.

Crystal Mangum, 34, cried as a jury on Friday unanimously found her guilty of the second-degree murder of Reginald Daye, 46. She was sentenced to a minimum of 14 years in jail.

Mangum, who is black, was notorious for triggering a racially charged case against three white students at North Carolina's Duke university. Hired as a stripper at an off-campus party for lacrosse players, she later accused three of them of gang raping her in a bathroom, generating global headlines about racism and abuse of privilege at elite schools.

The students were exonerated after Mangum's story fell apart. Charges were dismissed and the prosecutor, Mike Nifong, resigned amid claims he had breached professional rules of conduct in the case.

Friends said Mangum, a mother of three, struggled with her notoriety and embarked on a series of volatile relationships. On 3 April 2011 she stabbed Daye during a row. She told the trial he was beating her and in self-defence she "poked him in the side" with a kitchen knife.

"He straddled me, hit me, and then he started choking me," she said. "I couldn't breathe. My head hurt real bad. I was just trying to survive and I felt like Reginald was trying to kill me."

In a call to emergency services immediately after the stabbing Daye's nephew told the operator: "It's Crystal Mangum. The Crystal Mangum. I told him she was trouble from the damn beginning."

Daye died of his wound 10 days later.

A year before the stabbing, the trial heard, Mangum trashed another boyfriend's car, set fire to his clothes and almost burned down her home with her children inside. Daye's family requested the maximum sentence, saying he was loved and did not deserve his fate. The jury took six hours to convict.