Yesterday (July 30), news broke that Drew Barrymore's half-sister, Jessica Barrymore, was found dead in a car in National City, Calif.

Marta Lopez, who found 47-year-old Jessica's unresponsive body, reports that there were white pills scattered inside the vehicle. While no official coroner's report has been released, Drew's half-brother, John Barrymore, believes Jessica's cause of death was likely an accidental overdose.

"It looks like it was a drug misadventure. Mixing alcohol and pills. I seriously doubt she took her own life," John told the New York Daily News. He added that the car contained empty vodka bottles and "a couple bags of meth" (although this has not been confirmed by officials).

John went on to compare Jessica's tragic death to the untimely passing of a celebrity.

"My guess is that it was the booze and pills, like with Heath Ledger," he said.

Jessica's body was discovered by Lopez around 6AM on Tuesday (July 29). Later that day, the Medical Examiner’s Office confirmed to ABC 10 that the body was identified as Jessica Barrymore, Drew's half-sister.

The following day (July 30), the famed actress sent her condolences to Jessica's family.

“Although I only met her briefly, I wish her and her loved ones as much peace as possible and I’m so incredibly sorry for their loss,” Drew said in a statement to the Daily Mail (quote via New York Daily News).

John reflected fondly on his deceased sister, saying, “I’m going to miss Jessica. She was a kindred spirit. She knew laughing is what saves us all."