DURHAM - Crystal Mangum, who is charged with killing her boyfriend last year, will be allowed to represent herself during her murder trial, a judge decided Wednesday.

“Frankly, what you are asking me to do is extremely rare,” Superior Court Judge Jim Hardin told her. “And honestly, I have never seen it turn out very well for a defendant.”

Mangum, 34, is charged with first-degree murder in the death of Reginald Daye, 46, who died at Duke Hospital 10 days after Mangum stabbed him in April 2011.

Mangum gained national notoriety after accusing three Duke lacrosse players of rape in 2006. The charges were discredited in a high-profile saga that cost then Durham District Attorney Mike Nifong his law career.

Mangum contends she stabbed Daye in self-defense. She said she has “trust issues” with her attorney Woody Vann, and that they disagree on how the case should move forward.

Mangum said Vann refused to give her a second autopsy by a medical expert he hired, has only shared “half of the discovery,” and offered a plea agreement two months ago in which she would get time served in exchange for pleading guilty to assault with a deadly weapon.

Vann told Hardin that a medical expert was hired as a consultant, but not to generate a new report. Durham County Assistant District Attorney Charlene Coggins-Franks said the state hasn’t extended a plea agreement.

Mangum said she thinks the expert’s report would prove Daye died from a medical mistake, not – as the medical examiner’s report states – the stab wound.

“I would like to represent myself so that I can file these motions and get all the evidence out in the open,” said Mangum, who wore orange jail scrubs. “So the prosecution will know exactly what they are dealing with.”

Hardin appointed Vann as “standby” counsel, which means he will sit behind Mangum and assist her, but not address the court directly.