Mitchum, a promising young actor with an Oscar nomination behind him, was nabbed in a marijuana sting by LA cops during a raid on a house in Laurel Canyon in 1948.
Partying with actress Lila Leeds, dancer Vicki Evans and bartender turned real estate agent Robin Ford things were going swell until Detective Sergeant Alva Barr and his partner dropped in uninvited.
What they brought was "Trouble" as they soon hauled off the party for narcotics possession after they found a reefer stub under the couch. Another "muggle" was encased in Leeds' lipstick stained cigarette.
Outside reporters and photogs went crazy as they had been tipped to the big celebrity dope bust prior.
Mitchum's career seemed over as he seemed "In the Grip of Demon Drugs" -- a dancing slave to commie controlled "Indian hemp" known to hipsters as "cannabis sativa".
Mitchum was promptly booked and jailed as a sensational trial played out in the media.
Meanwhile, RKO studio boss Howard Hughes and his legal ace Jerry Geisler went to work trying to prove a frame- up.
Unfortunately for Mitchum, the jury returned a guilty verdict in less than 60 minutes.
The judge sentenced both Mitchum and Leeds to a year in the county jail but suspended sentence, placing them on probation for two years with 60 days in the county jail.
Mitchum exchanged his designer suit for jail-house denim blues, becoming Prisoner 91234.
After reporters caught him mopping up the filthy hellhole for a Page One photo op, Mitch got the lowdown from a jail trustee at mess.
"They wanted to make me for the whole deuce," Mitchum later said. "They didn't want to be wrong. I didn't know which side of the fuzz it was. Man, they can do anything they want - you know, charge you with some minor infraction of the rules and you end up doin' two big ones in Quentin. No f***in' way. I couldn't hack THAT."
Mitchum was released when his sentence was completed without incident.
"I've been happy in jail," he told the waiting throng of press, carefully choosing his words for mass appeal.
"Nobody envied me. Nobody wanted anything from me. Nobody wanted my bars or the bowl of pudding they shoved at me through the slot. I did my work and they let me alone."
"I'm through with my so-called pals. I'll see only my wife, my two children, and a couple of close friends.
"Parties? I'd stand out like a monster at a party. I'm typed a 'character' and I guess I'll have to bear that the rest of my life."
Mitchum then told press he was going back to work as soon as he could.
"I've got to. I'm broke.
"And now, if you'll excuse me, I'm heading for home."
The Big Dope Bust of 1948 was barely a blip in Robert Mitchum's long career as the public admired his refreshing tough-guy honesty. Modern day punks could only hope to be so cool.