What Happens After Once Upon A Time In Hollywood

In real life Charles Manson and the Manson Family were arrested a few months after the murders and eventually tried for them, yet it's not much of a leap to suggest that Manson would've eventually found himself in jail in the world of Tarantino's movie also.

For starters, after the foiled attempt to murder Rick and Cliff, it's highly probable that Flowerchild (Maya Hawke), the getaway driver who ultimately abandons the Family, would've eventually been apprehended and revealed Manson's murder plot to the authorities.

Flowerchild is very clearly based on Manson getaway driver Linda Kasabian, who ultimately turned state's evidence against Manson and helped secure his conviction.

In this alternate reality, Flowerchild's testimony likely would've been enough to get Manson brought up on charges for conspiracy to commit murder, which can itself result in life imprisonment.

Manson may not have died in jail in this new reality, but he certainly would've spent his prime years there.