A happy Ryan O'Neal returned from a birthday party for his longtime love Farrah Fawcett to find his son Redmond tied up in a dog run by his brother Griffin O'Neal.
That shocking sight was the REAL trigger behind Ryan's Feb. 2 rampage — climaxing with his arrest for assault and a handgun offense, The National ENQUIRER has learned exclusively.
Now O'Neal's other son Griffin has vowed to have his father charged with attempted murder!
Ryan, 65, and Griffin, 42, got into the early morning confrontation shortly after the elder O'Neal returned from the bash.
Accounts of what occurred differ — but Ryan claims Griffin was the aggressor, who picked up a fireplace poker and started swinging it. The actor says his son aimed at his head — grazing him four or five times.
"I ducked," says the burly film star. "He hit his own girlfriend in the head."
Ryan insists he got his gun and fired it simply to scare off his out-of-control son.
But an outraged Griffin tells a different story.
"I'm pressing attempted murder charges," he told a friend. "My dad's a madman — he tried to kill us!"
The friend says Griffin was in the house with his 22-year-old girlfriend Joanne Berry — who's seven months pregnant with his first child — when Ryan returned from the party and went ballistic.
The violent outburst was sparked by a bizarre chain of events, The ENQUIRER has learned.
While Farrah and Ryan were out, Griffin and his girlfriend were acting as "minders" for 21-year-old Redmond, who has a long history of drug abuse.
"They found Redmond — whom they claim had been smoking PCP — unconscious in his bedroom," said an insider.
"They thought he was dead and called paramedics. When ambulances and fire department personnel raced to the house, they revived Redmond — but he refused to go to the hospital.
"Griffin then chained Redmond in the dog run with a rope around his neck so he couldn't get to any more drugs. Griffin thought he was saving Redmond from himself.
"But Ryan exploded when he came home to find his youngest son chained up like a dog. There was a noose around his neck and his legs were roped."
The friend says Griffin told authorities his father struck both him and his girlfriend with the fireplace poker — and that Ryan inflicted a bloody wound to his chest that went through three layers of clothing and required stitches.
"Griffin also claims his girlfriend was smashed in the face with the poker — and had 16 stitches to close her facial wounds. He says she will need reconstructive surgery."
The insider tells a somewhat different — but equally frightening story.
"After Griffin was attacked with the poker, he flung a heavy glass ash tray at his dad, who ducked, and it hit Joanne in the face and caused her injuries.
"After the poker attacks — as Griffin and Joanne were being treated by medical personnel outside the Malibu house — Griffin remembered he'd left his dog in the house.
"When Griffin went back in, Ryan apparently shot at him and missed. The bullet went into a wall, not injuring anyone.
"The firemen and paramedics outside heard the shot and called cops, who arrested O'Neal and took him to jail."
Griffin insists his father tried to kill him, says the friend. "He wants him charged with attempted murder. He's claiming, 'My dad went off his rocker.'"
A ruffled Ryan was booked by Los Angeles County Sheriff's Deputies and released around 5:30 a.m. after posting a $50,000 bond.