LOS ANGELES, JUNE 17 -- In an extraordinary drama played out on live television, O.J. Simpson tonight surrendered to police on murder charges after a long, slow freeway pursuit and nearly an hour of tense negotiations.

Simpson, one of America's most famous and revered athletes, was charged with last Sunday's murder of his ex-wife and her male companion. He was taken into custody in the driveway of his west Los Angeles mansion at approximately 8:45 Pacific time after returning to his home in a friend's white Ford Bronco followed by at least a dozen police cars and helicopters.

The former football superstar had held his pursuers at bay throughout the 50-mile chase by reportedly holding a gun to his head and then remained in the car while negotiating with police. Simpson, clasping a family photograph, was coaxed out of the car by a police negotiator, who then persuaded him to enter the house, where he was taken into custody, according to police officials. He was then allowed to telephone his mother and was given a glass of orange juice. Police said they found a gun in the car.

Simpson was held without bail and placed under a 24-hour suicide watch. His friend, Al Cowlings, was also arrested, charged with aiding and abetting a fugitive and held on $250,000 bail. After being booked, both men were taken to the Los Angeles County Jail.

"I can't express the fear I had that this matter would not end the way it did," Simpson's lawyer, Robert L. Shapiro, told reporters outside Simpson's house. After praising police for their peaceful resolution of the standoff, he pleaded with the public to "reserve judgment" on Simpson's guilt "until evidence is reviewed."

The Bronco, driven by Cowlings, a longtime friend and former teammate of Simpson's, was spotted by police earlier in the evening in nearby Orange County. A police detective had a series of conversations with Simpson on his cellular telephone while police cleared a path for the bizarre procession that eventually wound its way back to Simpson's home. Simpson, 46, had begun his flight almost eight hours earlier, when he disappeared from a secluded house in the San Fernando Valley where his lawyer had arranged for him to surrender to police this morning.

His surrender eased fears that he would commit suicide. Shapiro had raised that possibility earlier in the day when he described his client as severely depressed and released a rambling, desperately emotional letter Simpson had given him before fleeing.

In the letter, Simpson denied he had killed Nicole Brown Simpson, 35, and Ronald L. Goldman, 25, accused the media of savagely twisting events and strongly suggested he would commit suicide to spare his two young children further public embarrassment.

"Don't feel sorry for me, I've had a great life, great friends" the letter concluded. "Please think of the real O.J., not this lost person."

The dramatic chase along miles of freeway was the most stunning development in a remarkable day that began with law enforcement officials announcing that Simpson would be taken into custody imminently and charged with two counts of murder. If convicted on both, he could face the death penalty.

But police and prosecutors later acknowledged they had lost track of Simpson's whereabouts during the course of their investigation and could not make an arrest. They said they had counted on Shapiro's assurance that he would bring his client to downtown police headquarters by 11 a.m.

When Simpson did not appear, they contacted Shapiro again and said his client was then a fugitive. At that point Shapiro agreed to tell police where Simpson was staying and allow police to arrest him there. When the police arrived, however, Simpson had fled along with Cowlings, who had played football alongside Simpson at the University of Southern California and the Buffalo Bills.

"Mr. Simpson is a wanted murder suspect, two counts of murder, a terrible crime," said a visibly angered David Gascon, the Los Angeles Police Department Commander, announcing Simpson's disappearance. "We need to find him. We need to apprehend him. We need to bring him to justice."

A citywide bulletin was broadcast across police channels warning that Simpson was wanted and possibly armed. The California Highway Patrol was put on alert and police monitored flights at Los Angeles International Airport.

"I'm very confident we're going to find O.J. Simpson, because this is a man who can't hide too easily," said Los Angeles County District Attorney Gil Garcetti. "His face is well-known to millions of people."

Garcetti warned that anyone aiding the fugitive could be prosecuted and he condemned what he described as lax official efforts to deal with earlier charges of spouse abuse against Simpson. "We saw, perhaps, the fall of an American hero," Garcetti said.

Shapiro, a prominent criminal defense attorney, appeared before reporters hours later to explain how his client had slipped from his grasp at around noon and to plead for Simpson to surrender.

Shapiro said he was stunned to learn early this morning that Simpson would be charged. "We had been told they were investigating, they had not named him as a suspect and that the investigation would take at least another week," he told reporters.

After receiving a phone call from police informing him that murder charges had been prepared, Shapiro said he went to the San Fernando Valley house where Simpson had been staying, bringing along several doctors to examine and advise his client.

A delay then ensued, as a distraught Simpson told the lawyer he needed time to talk to his family, then called his children, his mother and his personal lawyer, to whom he dictated an amendment to his will, according to Shapiro. He also wrote three letters. Shapiro said Simpson then secluded himself with Cowlings, while Shapiro and the experts waited in a separate room for police to arrive.

When they did, Shapiro said he discovered that Simpson and Cowlings had vanished.

Shapiro, who said he had presided over the voluntary surrender of dozens of clients over the years, told reporters, "I have never felt worse in my professional career as a result of what happened today."

He pleaded with Simpson: "O.J., wherever you are, for the sake of your family, for the sake of your children, please surrender immediately."

At the same news conference, one of Simpson's closest friends, Robert Kardashian read from one of the three letters, a note that had a grim tone that was part self-justification and part regret.

In it Simpson said: "I can't go on. No matter what the outcome, people will look and point."

He began the letter, "I had nothing to do with Nicole's murder," denied he had ever physically abused his ex-wife but offered apologies to the Goldman family.

"Unlike what was written in the press, Nicole and I had a great relationship for most of our time together," Simpson wrote. He said he had greed to plead no contest to battery charges in 1989 only to put an end to "the press hype" over their marriage, which ended in divorce in 1992.

"As a last wish," the letter pleaded with reporters, "please, please, please leave my children in peace. Their lives will be tough enough."

He added: "I think of my life and feel that I've done most of the right things, so why did it end like this?

"I've had a good life. I'm proud of how I lived. Nicole and I had a good life together. All this press talk about a rocky relationship was no more than what every long-term relationship experiences." He called himself "totally loving and understanding of all she has been going through."

He signed the letter, "Peace and love, O.J."

Shapiro said doctors he had consulted viewed the letter as a suicide note. Asked if he believed Simpson was still alive, he replied: "I'm keeping my fingers crossed and praying we will be able to bring him into court and let the case be determined by a court of law."

Simpson was last seen in public Thursday afternoon at the funeral of his ex-wife in Brentwood, the west Los Angeles community where she lived and was killed, and later at a graveside service in nearby Orange County.

The bodies of Nicole Simpson, 35, and Goldman, 25, were discovered early Monday morning outside her town house in Brentwood, two miles from her ex-husband's house. Her body was found on the steps of the town house with multiple stab wounds and drenched in blood. Goldman's body was found a few feet away.

Simpson, who had a history of commiting domestic violence against Nicole Simpson during their marriage, was always the focus of the murder investigation. Police located the former athlete in Chicago the morning after the slaying -- he had arrived an hour earlier on a business trip for the Hertz rental car company -- and was asked by police to return to Los Angeles.

Police questioned him for three hours Monday. They impounded his car, searched the house where his ex-wife lived and began analyzing blood and tissue samples found at the scene.

Those blood samples were key to the charges brought today. District Attorney Garcetti said the samples, which reportedly matched Simpson's blood type, were the evidence that supported the murder charge. Garcetti said the weapon used in the killings was a knife, but provided no further details on the murders or the investigation that led to the charges against Simpson. Police officials added that they had not yet located the murder weapon.

Police said they believed Simpson had surrendered his passport to his attorney, but Shapiro said he had not received the travel document.

All day long, hundreds of people who seemed dazzled by the day's remarkable events milled about Simpson's luxury house on Rockingham Avenue in Brentwood, the late Nicole Simpson's town house two miles away and gathered at Parker Center police headquarters where he was supposed to surrender.

The prospect that a sports and media superstar was about to be charged with murder has fueled a media frenzy in Los Angeles, dwarfing even the long-running child abuse scandal involving singer Michael Jackson. Today's extraordinary string of events, however, seemed improbable even for Hollywood.

The day began with police announcing there would be an 11 a.m. news conference, and when word of the murder charges began circulating, it was assumed police would announce that Simpson had been taken into custody.

When police commander Gascon finally appeared, however, he delivered the stunning news: Simpson had been expected to surrender at 11 a.m., but he had disappeared. As an audible gasp went up from reporters, Gascon, his composure nearly broken, said: "The Los Angeles Police Department right now is actively searching for Mr. Simpson. The Los Angeles Police Department is also very unhappy with the activities surrounding his failure to surrender. We will be looking into those activities."

Garcetti's later news conference was more raucous, with reporters shouting questions demanding an explanation of how Simpson had been allowed to escape.

"We would have arrested him immediately if we'd known where he was," said Garcetti.

Staff writers Saundra Torry and Kara Swisher and special correspondent Kathryn Wexler contributed to this report.