Police say Mangum stabbed Reginald Daye, 46, in the chest during an argument at the apartment the couple shared in the 3000 block of Century Oaks Drive on April 3. Search warrants previously issued say Daye told responding officers Mangum stabbed him and took his money.
Daye was later taken off life support and died on April 6.
Mangum remains behind bars at the Durham County Jail under a $300,000 bond for assault charges. It is not known if a bond was set for the murder charge.
Mangum has said she feels she has been treated unfairly by Durham police ever since she falsely accused three Duke Lacrosse players of rape.