Carris-137 was born on December 15, 2510 in Ibrid, Tribute. At some point in her childhood, she was removed from her Phys Ed class by her principal, after she injured, even hospitalized, some of her classmates. Her principal stated that Carris seemed unaware of her own strength. She was abducted in 2517 along with the other SPARTAN-IIs.
In 2520, when a handler attempted to pin her, she reversed the pin, throwing the man and severing his fifth and sixth cervical vertebrae. This killed the trainer instantly. She was later seen crying outside her barracks. Doctor Catherine Halsey and Chief Petty Officer Franklin Mendez decided not to take disciplinary action. After the handler's funeral, Mendez spoke with her about the incident.