Manson Family Killer and Top Lieutenant Bruce Davis Dead at 83

Manson Family killer Bruce Davis -- who was considered one of Charles Manson's top lieutenants during their infamous, blood-soaked 1960s murder spree in Los Angeles -- is dead, TMZ has learned.

Davis died at exactly 11:03 PM on September 11 at the California Medical Facility in Vacaville, where he was incarcerated ... according to sources and the Solano County Coroner's Office. A cause of death was not released.

Like Manson, Davis was not present at the notorious Tate-LaBianca murder scenes in which 7 people were killed by other members of the Manson Family, including film director Roman Polanski's pregnant wife, Sharon Tate.

Debra Tate, Sharon's sister, tells TMZ ... "I always say a prayer upon their passing," referring to other Manson Family members who have died behind bars.

Debra adds, "Basically it says may they finally have clarity on the actions that they caused during their life, and may Lord have mercy on their souls."

The cult killers, many of them women known as the "Manson girls," were led by Manson's other top lieutenant, Charles "Tex" Watson, on those two nights of pure butchery, during which they scrawled messages -- such as "Helter Skelter" and "Political Piggy" -- in the victims' blood on the walls.

Manson and his followers were all convicted of the Tate-LaBianca murders and were initially sentenced to death, but after California abolished the death penalty, their sentences were commuted to life in prison.

Davis was convicted of the savage 1969 murders of Manson family friend Gary Hinman and stuntman Donald "Shorty" Shea. He confessed to police that he sliced Shea with a knife and was armed with a gun as Manson sliced off Hinman's ear with a sword.

Over the years, he was repeatedly denied parole. When he was denied parole in 2022 ... Davis' attorney Michael Beckman said the parole commissioner told him he "lacks empathy."

In January 2024, his parole hearing was postponed months after he appeared on the podcast "The Lighter Side of Serial Killers."

He wrote to host Keith Rovere in a 2023 Christmas card that he was "looking forward" to the parole board hearing before it was moved to August 2024, before being denied ... Fox News reported.