Laura Purviance, 24, was taken into custody at about 4 a.m. Friday at a rest stop on the 5 Freeway in the Valley of the Rogue rest area, about 13 miles north of Medford.
Los Angeles police found 61-year-old Caroline Purviance dead from a gunshot wound when they arrived at the scene Wednesday night. LAPD homicide officials described the incident as domestic violence and not a random act.
Purviance is being held in the Jackson County Jail.