Mangum was born and grew up in Durham, North Carolina, the daughter of Travis Mangum, a truck driver, and his wife Mary. She was the youngest of three children.[1] She attended Hillside High School, graduating in 1996.[10]
In 1996, Mangum filed a police report alleging that three years earlier, when she was 14, she had been kidnapped by three assailants, driven to Creedmoor, North Carolina, and raped. One of those she accused was her boyfriend, who was 21 at the time, which would be statutory rape. She subsequently backed away from the charges, a move relatives claimed was motivated by fear for her life. Mangum's father said he did not believe she was raped or injured, though her mother believed such an incident could have occurred—but not in 1993. She thinks it is more likely to have happened when Crystal was 17 or 18 years old, shortly before she made the police report.[1] Mangum's ex-husband, Kenneth Nathanial McNeill, believed the incident occurred as she said it did.[1]
After graduation from high school in 1996, Mangum joined the US Navy. She trained to operate radios and navigation technology. While serving in the Navy, Mangum married McNeill. Her marriage quickly broke down. Mangum reported to police that her husband had threatened to kill her, but the charge was dismissed when she failed to appear in court.[1]
She served for less than two years in the Navy before being discharged after becoming pregnant by a fellow sailor, with whom she went on to have another child.[1]
By 2002, Mangum had returned to Durham and was working as an exotic dancer. In 2002, she was arrested on 10 charges after stealing the taxicab of a customer to whom she had given a lap dance. This prompted a police pursuit at speeds of up to 70 miles per hour, occasionally in the wrong lane. After being stopped, Mangum nearly ran over a police officer, succeeding only in hitting his patrol vehicle. She was found to have a blood alcohol content of over twice the legal limit. Ultimately, Mangum pleaded guilty to four counts: assault on a government official, larceny, speeding to elude arrest, and driving while impaired, serving three weekends in jail, paying $4,200 in restitution and fees, and being given two years' probation.[1]
In 2004, Mangum earned an associate degree from Durham Technical Community College, and subsequently enrolled full-time at North Carolina Central University. At the time of the rape allegations, she was in her second year, studying police psychology, and earning a 3.0 average.[1]