Prosecutors were considering Thursday whether to charge Ryan O'Neal with assault with a deadly weapon for firing a gun during a brawl with his older son at the actor's Malibu home.

A sheriff's detective submitted results of an investigation to the Los Angeles County district attorney's office Wednesday.

"The detective presented the charges that were based on the arrest" but didn't make a formal recommendation, said Lt. Steve Smith of the Malibu-Lost Hills sheriff's station.

The case was under review and it was unclear when or whether charges would be filed, said Jane Robison, a spokeswoman for the district attorney.

Meanwhile, the battle between O'Neal and his son Griffin last weekend was sparked when O'Neal found his other son Redmond tethered to a staircase, TMZ.com reported Thursday.

Unnamed law-enforcement officials told TMZ.com that when Ryan O'Neal returned from dinner Friday night to Griffin O'Neal's house, he found Redmond, whose mother is Farrah Fawcett, tethered to a staircase with handcuffs on his ankles.

Griffin O'Neal allegedly chained his half-brother to the banister to prevent the 22-year-old from buying drugs, sources told TMZ.com.

Earlier in the evening, Griffin O'Neal called 911, apparently believing that Redmond O'Neal had overdosed, but paramedics found Redmond awake, TMZ.com reported.

Click here to read the TMZ.com report.

O'Neal's attorney, Mark Werksman, said Wednesday that Redmond is currently in drug treatment.

On Wednesday, attorneys for both father and son charged that the other side was responsible for the fight that later ensued in which a fireplace poker was swung and a gun fired.

Griffin O'Neal, 42, and his pregnant girlfriend, Joanna Berry — who had bandages around a bruised and swollen left eye — appeared but did not speak at a Wednesday press conference held by attorney Gloria Allred.

"We vigorously reject any assertion that the injuries suffered by Joanna and Griffin were as a result of Ryan O'Neal's acting in self defense," Allred said in a prepared statement.

Werksman countered quickly.

"Ryan O'Neal is the victim and was attacked by his own son, with his own poker," said Werksman, who noted his client had a cut on his hand and bruises on his arms and legs as a result of the dispute.

Berry, who is expecting a baby boy at the end of March, suffered facial lacerations that took eight stitches to close, as well as head trauma and a corneal abrasion during the confrontation, Allred said.

Ryan O'Neal, who was arrested for investigation of assault with a deadly weapon and negligent discharge of a firearm, has said he fired a "warning shot" to scare his son away after he came at him with the poker. He said his son struck Berry, 25, with the poker when he ducked during the fight.

Sheriff's officials said they hope to present the O'Neal case to the district attorney's office by Friday. County prosecutors will review the findings to decide whether charges should be filed.

Allred said her clients would not speak to reporters because they may be called to testify if a criminal case is filed.

Asked if Griffin O'Neal was under the influence of drugs the night of the fight, Allred said he was not.

Werksman said he and his client believe Griffin O'Neal was drunk at the time and became violent when his father asked him to leave. The attorney added that his client was sober at the time of the incident.

Allred declined to answer questions about whether a civil lawsuit will be filed, but Werksman said Ryan O'Neal financially supports his son.

The O'Neals' problems have a long history.

In 1983, police came to a home after a fight in which the elder O'Neal knocked out two of Griffin's teeth. No charges were filed, but the younger O'Neal entered a drug rehabilitation center in Hawaii soon after.

Griffin O'Neal was found guilty of reckless boating in a 1986 accident that killed Gian-Carlo Coppola, son of film director Francis Ford Coppola, and got an 18-day jail sentence for failing to perform 400 hours of community service as ordered.

He pleaded no contest to drunken driving in 1989 and was sentenced to probation. In 1992, he avoided a possible three-year jail sentence by pleading no contest to charges he shot at an estranged girlfriend's unoccupied car. He agreed to spend a year in a live-in drug rehabilitation program and serve five years' probation.

Berry's first name and age provided by Allred were different from those reported by authorities. Sgt. Ken Scheurn at the Malibu sheriff's station said their records list her as JoAnne Berry, 22.

The Associated Press contributed to this report.