The body of Martha Rodezno, 51,was discovered on the northbound 5 transition ramp to the westbound 22 Freeway around 2:44 a.m. on Dec. 8.
Witnesses said they saw Rodezno being ejected from the passenger side of a petroleum tank truck and that the driver kept going.
Detectives said they later obtained evidence showing that Rodezno got into a tank truck driven by 33-year-old Jaqwun Laerin Turner.
Turner was interviewed by homicide detectives. He was arrested at his home on Wednesday and booked for hit-and-run with permanent injury or death.