O.J. Simpson was freed today after a jury acquitted him of the bloody double murders of his ex-wife Nicole Brown Simpson and her friend Ronald L. Goldman, ending a marathon trial that transfixed much of the nation for months.

Wincing and whispering "thank you thank you," Simpson, who spent the past 15 months in jail, smiled weakly at the jury and embraced his defense lawyers as Judge Lance A. Ito ordered him "transported to an appropriate sheriff's facility and released forthwith."

Relatives of the murder victims appeared stunned by the verdicts, some weeping in anguish as the jury foreman announced Simpson not guilty on both murder counts. Nicole Simpson's parents and three sisters sat stone-faced in their courtroom seats while Goldman's sister and stepmother hung their heads and cried, collapsing into the arms of father Frederic Goldman, who stared straight ahead and gently stroked his daughter's long hair.

Simpson's oldest son, Jason, doubled over, weeping into his hands, while his aunts and sister wiped away tears of relief and raised their eyes as if in silent prayer.

Simpson's lead attorney Johnnie L. Cochran Jr. slapped his client's back in exultation as he heard the verdict read. Prosecutors Marcia Clark, Christopher Darden and William Hodgman stared blankly at the jury, which rejected their elaborate case in less than four hours of deliberations.

In a statement read to reporters by Jason Simpson an hour after the verdict O.J. Simpson said, "I am relieved that this part of the incredible nightmare that occurred June 12, 1994, is over." Simpson said his "first obligation is to my young children" and his "second obligation is to my family and friends who never wavered in their support."

With his acquittal, Simpson said "I will pursue as my primary goal in life the killer or killers who slayed Nicole and Mr. Goldman. . . . They are out there somewhere. . . . I would not, could not and did not kill anyone."

When the verdict was announced, crowds of Simpson supporters erupted into victory cheers outside the besieged courtroom in downtown Los Angeles. The victims' families were escorted from the courtroom by deputies who moved them down a back stairway to shield them from the crowds inside and outside. Observers said the relatives wept and clutched each other as they staggered by silent onlookers.

In a scene briefly reminiscent of last year's freeway chase, national television viewers watched as helicopters followed a white minivan carrying Simpson away from the jail. He initially left the jail with a police escort, but it quickly peeled off as he headed for his home at 360 Rockingham where he was met at the door by his old friend Al "A.C." Cowlings, who hugged him for nearly a minute.

The predominantly black and female jury found reasonable doubt to believe that Simpson committed the murders after hearing nine months of testimony, including more than 100 witnesses and impassioned pleas from prosecutors and defense lawyers to "do the right thing."

The verdict brought to a sudden end the "Trial of the Century" that had grown over more than a year to a form of national media addiction, mesmerizing millions of television viewers, dominating news coverage and provoking widespread debate about issues of domestic violence, racism, the jury system and police misconduct.

Simpson, a former football superstar who had made a second career as an actor and commercial spokesman, had lived almost entirely in his jail cell and Ito's well-known courtroom since June 17, 1994, when he was arrested after a nationally televised slow-speed freeway chase in Los Angeles, less than a week after the killings.

Cochran said during the trial that in the event of an acquittal, Simpson would want to spend an extended period out of public view, but would eventually emerge to thank his supporters in the public and to answer questions "in an appropriate forum."

Simpson's lawyers had been working for several months on plans for the aftermath of the trial, including negotiations toward a pay-per-view victory interview and celebration.

The verdicts leave Simpson free to pursue his career. Even if new evidence emerges in the murders, Simpson cannot be tried again by the state because of the U.S. Constitution's Fifth Amendment, which prohibits prosecuting someone twice on the same offense.

Both the Browns and Goldmans have filed suit against Simpson for the wrongful deaths of their daughter and son. These suits could continue despite the verdicts. Simpson's youngest children, Sydney and Justin, have been living with Nicole Simpson's parents.

The Simpson case had sparked fears of racial tension, and Los Angeles police went on a full-scale tactical alert early today. Police stressed that the alert, which put hundreds of extra police on the streets, was merely a precaution.

Cochran rejected the notion that the verdict turned on racial appeals made in closing arguments, saying that the acquittal was based on flaws in the evidence against Simpson.

"The time-line was the key," defense lawyer Barry Scheck said on NBC. "It really was impossible for Mr. Simpson to have made those thumps on the wall." The defense repeatedly succeeded in punching holes in the prosecution time-line, he said.

Simpson's niece Cynthia Baker, said after the verdict that the family had been praying for today's result. "We hoped that the jury would be fair . . . that God would lead them."

Baker said her first words to her uncle would be: "Happy to have you home, praise God."

When asked what she would say to the families of the victims, she said, "We're praying for them, and one day we hope the killers of their daughter and son will be found."

The sole black male juror on the panel, a 43-year-old phone company salesman, raised his fist toward the defense table, and a 38-year-old female health specialist wept as the group filed out of the room, courtroom observers reported.

The jurors, who had been sequestered since mid-January, indicated unanimously before the verdict was read that they did not want to speak with reporters or any of the trial attorneys afterward.

Much of America was watching televised broadcasts from the courtroom as the verdicts were announced. At the White House, spokesman Michael McCurry said President Clinton watched the verdict in a small room next to the Oval Office and then wrote out the following statement:

"The jury heard the evidence and rendered its verdict. Our system of justice requires respect for their decision. At this moment our thoughts and prayers should be with the families of the victims of this terrible crime."

Simpson pleaded not guilty at his first arraignment more than a year ago and hired a multimillion-dollar "Dream Team" of more than a dozen expert trial attorneys, including some of the biggest names in the profession, to argue from the start that he was wrongly accused by police and prosecutors.

The defense went on to charge that racist police officers had conspired to plant evidence to frame the African American celebrity, and that prosecutors eager for a big conviction had deliberately overlooked signs of the plot.

Prosecutors charged from the beginning that that Simpson slashed his ex-wife Nicole Simpson, 35, in a last violent spasm of rage culminating a 17-year relationship characterized by passion and abuse. Prosecutors contended that the Simpson's genial and affable public persona masked a dark, possessive, obsessive side that had propelled him to beat his wife during their marriage, stalk her after they separated and kill her in a final effort to control her.

Nicole Simpson's friend, Goldman, a 25-year-old waiter, was killed because he was in the wrong place at the wrong time, prosecutors alleged. Goldman apparently confronted the murderer when he arrived at the gate outside her town house condominium on an errand, delivering eyeglasses dropped by her mother at the restaurant where he worked. Prosecutors theorized that he was killed because he witnessed her slaying.

Prosecutors lacked an eyewitness or murder weapon, but spent months laboring to construct a mountain of circumstantial evidence to show that Simpson had the opportunity and motive to commit the murders and had left blood, hair, fibers, a hat and gloves that pointed to him as the killer.

Prosecutors Clark and Darden implored the jurors to reject the allegation of a conspiracy and see the evidence as pieces of a puzzle that told a chilling story. After his arrest, Simpson was quickly surrounded by friends who included some of Los Angeles' most prominent lawyers.

Less than one month after the murders, the defense had begun spelling out its conspiracy theory, leaking to the New Yorker the notion that police had framed Simpson and that then-Detective Mark Fuhrman was a racist who had a motive to plant evidence.

A drumbeat of publicity bolstering the defense case followed throughout the summer and fall, as the immense public interest in Simpson merged with the defense scramble to find experts and lawyers who would challenge every aspect of the state's case.

Cochran assembled a team of defense attorneys specializing in DNA testing, blood evidence and police corruption.

The Simpson jury was a product of the relatively new art of jury selection by consultants who examine everything from the jurors' syntax to their home furnishings. But the immense pressure of the sequestration, news media pressure and the celebrity of the defendant combined to force out several jurors during the trial. Other jurors were excused after allegations that they sought to cash in on their selection by making book deals or keeping trial diaries.

Finally, the jury played a role in policing itself, as rifts among jurors led to accusations of racial animosity and petty behavior. For months, it seemed questionable that 12 jurors would survive the traumatic trial.

Legal analysts said that the extreme stress of total sequestration likely contributed considerably to the ease with which the jury reached unanimity.

"The longer they live together, the more they bond, and they begin thinking alike in so many ways," said Chicago defense lawyer Michael Pope, a past president of the International Association of Defense Counsel. This is an extra edition of Tuesday's Washington Post. Only the stories about the Simpson verdict have been updated from earlier editions of the paper. Wednesday's Post will contain extensive coverage of the verdict, including a special section of stories and photos from the 10 Post writers and photographers now in Los Angeles. Digital Ink, The Post's on-line service, will carry late news on the verdict throughout today and tonight. CAPTION: O.J. Simpson reacts as the verdicts are read. Embracing him is attorney Johnnie L. Cochran Jr.