The 47-year-old is half-sister to actress Drew Barrymore and daughter to John Barrymore and Nina Wayne.
Jessica's body was discovered inside her car around 6 a.m. by Marta Lopez. Lopez told ABC 10 News the vehicle was blocking her driveway, and she walked over to see if the woman behind the wheel needed help. Jessica was in the driver's seat and had an energy drink between her legs, but did not appear to be breathing and had dozens of white pills scattered on the passenger seat. Lopez then called police.
"Her car was parked right here around midnight," Oscar Sandoval added. "I thought she was sleeping or waiting for someone ... It's crazy. It's sad to see that."
The Medical Examiner's Office has confirmed they have Jessica Barrymore's body, whose date of birth, July 31, 1966, is the same as Drew's half-sister. The cause of death is currently unknown, but some speculate it may have been a suicide. Jessica would have turned 48 years old on Thursday.