LONDON -- Three years before Jimmy Savile, one of Britain's most popular television hosts, came under public suspicion as a prolific pedophile, the police dispatched to prosecutors a thick investigation file by secure e-mail and courier van detailing four allegations of sexual abuse against him.
The confidential file, compiled from 2007 to 2009, contained witness statements and "significant and solid evidence," according to a former senior officer with the Surrey Police, a force outside London that conducted a two-year investigation into Mr. Savile. Recently, amid allegations by hundreds of women and at least two men that Mr. Savile used his fame and influence as a shield to abuse them as children, Britain's Crown Prosecution Service said in a statement that the case was dropped because a crucial witness declined to testify and because there was "insufficient evidence for a realistic prospect of conviction."
But at the Surrey Police headquarters, the former senior officer said, those who investigated the case felt that prosecutors were hesitant to confront a man who had spent decades building a cult of celebrity in Britain that few could match. Mr. Savile's popularity and power rested on his blend of flashy showmanship on top-rated prime-time BBC programs, working-class chumminess and charitable endeavors that attracted powerful friends and patrons in royal palaces, Parliament and the highest ranks of the police.
"Really, it came down to this: do we really want to take on this man, Saint Jimmy, who does all of this fund-raising and knows all of these people?" the officer said.
Despite widespread suspicion about Mr. Savile's behavior over decades, and Mr. Savile's acknowledgment in his autobiography that he had a predilection for young girls, the prosecution that was halted in 2009 was one of a number of missteps and missed signals that allowed Mr. Savile to escape legal scrutiny for most of his career, according to accounts from police officers, victims and those who knew and worked with him.
Seven police investigations were begun into Mr. Savile's sexual activities before he died last year just shy of his 85th birthday, according to British news reports, but officers have said that separate police forces across Britain were unable to connect the dots, partly because a national crime database did not come into full operation until 2010. Mr. Savile's connections and fame made pursuing sometimes hazy allegations against him unpalatable, others familiar with those investigations said. Newspapers, afraid of Britain's strict libel laws, decided not to publish their suspicions, although several had conducted their own investigations over the years.
Along the way, Mr. Savile cultivated police officers he met at corporate functions or community events, meeting regularly with many of them at his penthouse apartment in Leeds, the northern industrial city that was his hometown, according to an account in The Times of London.
"Most of the officers who attended the 'club' at Savile's home were from the West Yorkshire Police, the force now investigating claims that Savile abused vulnerable children while working as a volunteer at Leeds General Infirmary," the newspaper said.
Mr. Savile's behavior continued despite a series of publicly known sexual episodes and other warning signs involving young people, including one occasion when he groped a girl on live television. A new police investigation, a review by the Prosecution Service of the file it set aside in 2009, hearings by a parliamentary committee, and three inquiries at the BBC, as well as new investigations by the schools, hospitals and mental institutions Mr. Savile frequented on his charitable rounds, are now asking the same question as many Britons: how did one of the nation's best-loved entertainers, a household name, get away with so much for so long?
Mr. Savile's autobiography, "As It Happens," published in 1974, when Mr. Savile was 48, did not seek to hide his appetites. Years before he became a famous television host, Mr. Savile recounted, a police officer asked him to look out for a young girl who had run away from a home for juvenile offenders.
Mr. Savile told the officer that if she went to the nightclub in the north of England that he ran at the time he would hand her over to the authorities, "but I'll keep her all night first as my reward." The girl did go to his nightclub and did spend the night with Mr. Savile, he wrote. A police officer was alarmed, but he said he dissuaded her from bringing charges against him.
He described another instance when he was accused of openly fondling a young woman on a terrace of the House of Commons and causing her to cry out in distress and others to break from their discussions and rush to her aid. "All was eventually sorted out," Mr. Savile wrote.
In the book, Mr. Savile admitted that he became a "boyfriend" to girls at a youth club and that he felt, on a trip to California, that it was "criminal that the age of consent in that admirable state is 18."
In the following years, despite those admissions, he appeared as a celebrity endorser on the covers of public information booklets titled "Stranger Danger" and "Other Peoples' Children," which warned children to be wary of unsavory adults and provided advice for child care givers.
Few men in living memory, perhaps none in Britain, have undergone such a rapid descent from public adulation to almost universal loathing as Mr. Savile. His fame, though it never traveled much beyond Britain, made him a huge if improbable star in an era when the BBC's reach was unparalleled.
He had dyed-blond shoulder-length hair, puffed on cigars and specialized in corny stage routines. He had a penchant for gold chains and rings, drove a succession of Rolls-Royces with personalized "JS" license plates, and was renowned for his cheeky hobnobbing with many of the most iconic cultural, political and religious figures of the second half of the 20th century. His television programs drew as many as 20 million viewers, and guests like Elvis Presley and Muhammad Ali, at a time when Britain's population was barely 50 million.
Two tribute documentaries, broadcast by the BBC in the weeks after Mr. Savile's death, emphasized the reach of his celebrity. One photograph included in the documentaries showed him getting a papal knighthood and Pope John Paul II placing a hand on his shoulder. Another showed him in a traditional calf-length morning suit and top hat when he was given his British knighthood by Queen Elizabeth II. "For six decades," the narrator said in one of the documentaries, he was "part of the fabric of British life."
Anne-Marie McAlinden, an expert on sexual abuse at Queen's University Belfast, said Mr. Savile had used his influence to groom not just his victims but also the entire society. "Not only did he abuse his position of trust and authority, which was amplified because he was a celebrity," she said, "he extended it to the whole organization, to the BBC and even the press."
Alicia Alinia, a lawyer who represents about 30 women and men who have alleged abuse by the entertainer over a period of five decades, said Mr. Savile fit a pattern of child abusers. "He abused where there was an opportunity to do so, and what he really capitalized on was his celebrity," she said. "This case is steeped in the power structure of abuse, and how he manipulated that power."
In one instance, a video available on YouTube shows Mr. Savile appearing to grope a girl on live television, although the camera operator zoomed in to focus on Mr. Savile as the victim squirmed in alarm.
"Everybody -- the press, the police, people at the BBC -- they knew that things were going on with Jimmy Savile," Freddie Starr, an entertainer who appeared on Mr. Savile's shows and who has denied allegations he also abused children, told reporters last week. . "Everybody is guilty of this. You can put the finger on everybody at the BBC."
On Thursday, Mr. Starr, 69, became the second person, after the former punk-rock star Gary Glitter, to be arrested and questioned by police investigating the abuse by Mr. Savile.
In the Britain of the 1970s, said Vanessa Feltz, a British television and radio host whose career overlapped with Mr. Savile's, there was a naïveté among parents and an unquestioning trust of those who appeared on the BBC. "It was a climate," she said, "in which if Savile asked parents whether they would like him to give their child a ride in his gold Rolls-Royce" and visit his dressing room, they would have agreed without a second thought.
"If you were the sweet, smiling face of a program that everybody loved, lauded and applauded, you had to have passed some kind of qualifying badge of niceness to be there," Ms. Feltz said.
Interviewers asked Mr. Savile on several occasions about rumors of his sexual relationships with children. He denied the rumors, often in ways that seemed artfully constructed to leave audiences struggling to decide whether he was admitting to pedophile behavior -- and making a joke of it -- or simply mocking his accusers.
On a television show in 1999, a fellow panelist, Ian Hislop, editor of the satirical magazine Private Eye, asked the entertainer what he did in the trailer he used as a retreat when participating in fun-run events and other activities sponsored by his charities. "Anyone I can lay my hands on," Mr. Savile replied.
His abuse, and the influence that protected him, extended to his own family, according to an account that Caroline Robinson, Mr. Savile's great-niece, gave to a British television program, "This Morning." Ms. Robinson said that when she was 12, Mr. Savile touched her inappropriately as she sat on his lap. When she told her grandmother, she responded: "It's only Jimmy. Don't worry, I'll sort it out." Ms. Robinson has said that Mr. Savile abused her again when she was 15, but that no one confronted him.
"I describe it as a terrible, dark high-wire act," said Dan Davies, a writer who spent time with Mr. Savile at the end of his life while working on a biography. "He couldn't have made himself any more conspicuous or more odd or strange."
One person Mr. Davies spoke to who had worked with Mr. Savile in his early days said colleagues joked that "either he was going to be a huge success or in prison" for sexual relations with 14-year-old girls. His eccentricity, along with his "bulletproof shield of celebrity and philanthropy," was "a force field to avoid detection," Mr. Davies said.
Mr. Savile himself admitted, in video from 1972 that was broadcast in one of the tribute documentaries, that he realized that being different "had a tremendous effect on people." Many of the people he knew, he said, describing an anecdote from his years working in a coal mine, suspected that he was unusually strange. He told an interviewer they would say, if asked, that "he's not what you think you know; the forces of darkness are at work there."
A former press officer for the BBC, Rodney Collins, told reporters last month that he had been asked in 1973 by an executive at BBC Radio to look into whether the news media were pursuing a story on sexual abuse by Mr. Savile. Mr. Collins said he was told that, though newspapers had investigated rumors about Mr. Savile, they were loath to take on Mr. Savile because of his popularity. When Mr. Collins told his bosses at the BBC, he said, the matter was dropped.
The last page of Mr. Savile's autobiography described an episode in which five young girls stayed at his home. Around 11 a.m., their mothers came looking for them, but, Mr. Savile wrote, he had left the house and a male friend had hidden in the closet. "To date," he wrote, "we have not been found out. Which, after all, is the 11th Commandment, is it not?"
He died on Oct. 29, 2011, without ever facing a single charge in court.
Sandy Macaskill and Lark Turner contributed reporting.
This article originally appeared in The New York Times.