LONDON — British police and the country’s leading child welfare group drew a horrific picture of more than 200 cases of sexual abuse of children as young as 8 by the television host Jimmy Savile in a report released Friday, and prosecutors admitted for the first time that they could have brought Savile to trial before his death in 2011 but failed to do so.
The depiction of what Peter Spindler, a police commander, called a ‘‘vast, predatory and opportunistic’’ record of misconduct offered the latest gruesome indictment in a scandal that has plunged the BBC, Savile’s longtime employer, into crisis; drawn in a mounting tally of suspects and victims; and raised questions about the protection of children in supposedly safe institutions.
In the process, Savile’s public image has been transformed. Once seen as a zany national treasure with a near-saintly commitment to charitable work with children, — knighted by Pope John Paul II and Queen Elizabeth II — he is now blamed for one of Britain’s most extensive catalogs of abuse.
“It is clear that Savile cunningly built his entire life into gaining access to vulnerable children,’’ said Peter Watt, a senior official of the children’s advocacy group, the National Society for the Prevention of Cruelty to Children.
The report said Savile used his status as a celebrity to ‘‘hide in plain sight’’ as he committed criminal offenses in 28 police jurisdictions over nearly six decades.
The locations included the premises of the BBC, Britain’s public broadcaster; a home for disturbed adolescent girls; and 14 medical facilities like hospitals, mental health units, and a hospice. The cases covered the years 1955 to 2009. The youngest victim was an 8-year-old boy, the report said, and the oldest was 47.
Separately, the Crown Prosecution Service acknowledged that three victims who accused Savile of abuse in 2009 were not taken seriously enough.
“I would like to take the opportunity to apologize for the shortcomings in the part played by the Crown Prosecution Service in these cases,’’ Keir Starmer, the director of public prosecutions, said in a statement.
The report also did not challenge the assertions of Mark Thompson, the head of the BBC at the time, that he had no role in killing the Savile investigation and was unaware of the sexual abuse accusations until he left the BBC last September. Thompson is now chief executive of The New York Times Co.
According to the report, 73 percent of the victims were under 18. A total of 450 people came forward to accuse Savile after the scandal exploded in October, and the police concluded that the number of crimes he is accused of committing totals 214, 34 of them rapes.
The offenses peaked between 1966 and 1976, the report said.
“His peak offending came with the peak of his success,’’ said Detective Superintendent David Gray, who works in a Scotland Yard unit investigating sexual crimes against children.
The report raised some questions about the culture of the era in which Savile rose to prominence as television audiences grew, feeding in part on a revolution in pop music.
“It was an age of different social attitudes, and the workings of the criminal justice system at the time would have reflected this,’’ the report said.
In an introductory passage of the 37-page report, the authors addressed an issue that has caused concern among legal experts, Savile family members, and others who have argued for caution in face of the avalanche of allegations: Savile, who died in October 2011, cannot defend himself, nor can the accounts of his accusers be tested in criminal proceedings.
“An issue that has understandably been raised is that as Jimmy Savile is dead there can be no criminal prosecutions against him and the testimony of his victims cannot be challenged in the courts,’’ the report said.
But the authors, in effect, turned this argument on its head, saying that the ‘‘lack of criminal proceedings — and justice for victims’’ convinced them that the information gathered in their three-month investigation ‘‘should be put into the public domain.’’