The police report says Mattox clenched, breaking her friend's bed, angered the unidentified friend and started a fight.
Dallas police Sr. Cpl. Kevin Janse says at some point the friend picked up a butcher knife and asked Mattox if she was "ready to die." However, Mattox had no visible injuries when police arrived.
Janse says the friend left the apartment but before officers arrived and is being sought.