FBI investigated letters sent to Pistons' Daly

The FBI investigated a series of threatening letters sent to Detroit Pistons coach Chuck Daly at the height of his team's success during the 1989-90 "Bad Boys" championship era, newly released government records show.

The 67 pages, obtained by The Associated Press as part of a Freedom of Information Act request, detail how federal agents in Detroit ordered fingerprint, handwriting and even psycholinguistic analyses as part of an effort to determine who sent the correspondences.

Daly's teams played a punishing, in-your-face brand of defense that angered opposing players and coaches, and -- based on the content of the letters examined by the FBI -- fans, too.