Tulare police and firefighters were called out just before 2 am to Bardsley near Laspina for reports of a car crashed into a power pole.
Police arrived and found the car engulfed in flames, but it did not appear to be involved in a crash.
Fire crews were able to put out the fire but did not find a driver.
One of the firefighters found the body of a 57-year-old woman from Los Angeles in the trunk.
Detectives say they were able to identify 44-year-old Branden Bayilynn Howard as the suspect.
He was arrested later in the day for homicide.
Officials will not be releasing the woman's name until her family has been notified.