"We believe his involvement in these investigations was not looked upon with great favor by those at the university," Fox said.
He said he had no information about the target of the FBI raid, saying it could be related to Rifkin or the scrap-metal investigation, or something entirely different.
"Without equivocation, (Grady) denies wrongdoing in any of these matters," he said.
Grady told The Associated Press in a phone interview later Wednesday that he had not been contacted by authorities. Asked why authorities might be at his old workplace, he said, "I have no idea."
Controversy has dogged Grady before. After becoming Wisconsin's first black police chief in the mostly white town of Bloomer in 1989, he created a stir by issuing nearly 300 tickets, including to himself, for violations of a snow-shoveling ordinance.
When he became Santa Fe, N.M., chief in 1994, he ordered officers to stop accepting free cups of coffee on the job and banned bolo ties. Police responded with a 103-5 no-confidence vote in their boss. After digging in his heels for two years, Grady resigned, saying his reforms had encountered too much resistance.
Grady was placed on administrative leave on Nov. 10, along with another officer, for allegedly failing to pass on witness statements that might have benefited Rifkin as he mounted his defense against the sexual assault accusations.
Toward the end of November, Clay Campbell, the state's attorney in DeKalb County at the time, cited alleged mishandling of information by NIU police for dropping the charges against Rifkin. It was Campbell's successor who reinstated them last month.
Adding another layer to Rifkin's case is a civil lawsuit he filed earlier this year.
The suit, now making its way through U.S. District Court in Rockford, names NIU, Grady and other officers as plaintiffs. It alleges, among other things, that Rifkin was tricked by NIU officers into signing a confession regarding the alleged sexual assault.
All the plaintiffs have denied any wrongdoing.
Rifkin's attorney, Bruce Brandwein, said Wednesday his client intends to enter a not guilty plea to the criminal sexual-assault charges.
"He absolutely denies any wrongdoing," Brandwein said.