Michael Jackson announces plans for Summer residency at the O2 Arena at a press conference held at the O2 Arena on March 5, 2009 in London, England.

Police concerns that media-hungry terrorists would attack Michael Jackson's trial as a "soft target" led to a request for federal help, according to FBI files kept on the late pop star.

The documents also show that the FBI helped facilitate interviews in the Philippines by California authorities investigating Jackson over allegations that he had sexually abused boys.

The FBI monitored Jackson for more than a decade, but the files contain no major revelations about his private life and the bureau apparently never developed any solid evidence against him.

In 2004, the Santa Maria Police Department in California asked for FBI "involvement" after Jackson was arrested for child molestation. Police, according to the FBI, said they believed the court case would be a "soft target" for terrorism because of the "worldwide media coverage" the trial would attract.

The FBI concluded there were no threats, but did note the presence in an early court appearance of "The Nation of Islam, represented by its security unit Fruits of Islam," and of a New Black Panther Party member whose name was left blank in the files. Jackson used Nation of Islam bodyguards during the legal proceedings.

Back in September 1993, an investigator from the Los Angeles Police Department and another from the Santa Barbara Sheriff's Office arrived in Manila to speak to two former employees of Jackson's Neverland ranch who claimed they saw the singer fondle young boys.

Their trip came after the LAPD had asked the FBI if it wanted to work a possible case against Jackson for transporting a minor across state lines for immoral purposes. The FBI checked with the U.S. Attorney's Office, which declined.

The files say an FBI agent accompanied the California officials to the first interview to make sure there were no problems.

The documents, dating from 1992 to 2005, were made public Tuesday (Dec. 22) through a Freedom of Information Act request from the Associated Press and other media after Jackson's death June 25, at age 50. The FBI initially said it had about 600 pages in its files but released 333 pages, citing privacy rules and the desire to protect investigative techniques.

In March 2004, the Santa Barbara County district attorney's office reached out to the FBI, seeking help in developing a strategy to prosecute Jackson for molesting a 13-year-old cancer survivor in the singer's home. Jackson was acquitted of all 14 counts against him in what was one of the most widely followed cases in history.

The FBI reviewed case notes from local authorities and examined 16 computers taken from Jackson's home. Nothing notable was described as being found on the hard drives, though parts of the files are redacted.

Tom Mesereau, who was Jackson's lead defense attorney during his trial, said the FBI documents provide further proof the singer did nothing wrong.

"He was not a criminal and he was not a pedophile," Mesereau said. "The fact that so many agencies investigated him and couldn't find anything proves he was completely innocent."

A message left for Ken Sunshine, spokesman for the Jackson family, was not immediately returned.

The Santa Barbara case was the most recent time the FBI was asked to investigate Jackson but records show the agency had been looking at his alleged involvement with younger boys for more than a decade.

In September 1993, an FBI agent in London told colleagues in Los Angeles that the British press was reporting that a man was making allegations he had held a sexually charged phone call with Jackson in 1979, when the man was 13 and Jackson was 20. Aside from asking the information be passed on to local authorities in Los Angeles, the FBI agent in London noted that no further action was being taken.

In October 1995, the U.S. Customs Service asked the FBI to review a VHS videotape labeled "Michael Jackson's Neverland Favorites An All Boy Anthology" as part of a child pornography investigation. The recording was of such poor quality that investigators appear to have been unable to determine what was on it.

The files include death threats against Jackson, then-President George H.W. Bush and mob boss John Gotti that led to the 1993 sentencing of Frank Paul Jones, who allegedly was obsessed with Janet Jackson, Michael's sister.

The FBI includes an interview with an unidentified "victim," whose name is redacted but presumably Michael Jackson, who states that he was aware of the threats and took them seriously.

According to a 1992 Associated Press story, Jones was arrested June 22 and held on $15,000 bail for investigation of trespassing in the driveway of the Jackson family compound in Encino, Calif. The following year, he was sentenced to two years in prison for "mailing a threatening communication," according to a 1993 press report included in the FBI files.

(c) 2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.