Peg Brand, wife of Myles Brand and a philosophy professor at the school, pleaded on Thursday for an end to the threats against her family and others linked to Knight's firing.
"I have been forced to teach my class with a policeman at my side," she said. "This is not right."
On Sunday night, more than 2,000 students marched in protest of Knight's dismissal, burning effigies and knocking over light poles outside the president's campus residence. The Brands have also received threatening e-mails.
"You can imagine how a victim feels when a large group gathers and starts demonstrating like they did Sunday," campus police Lt. Jerry Minger said. "Any rational human being would have fear after that."
He said an officer is staying at the home.
In addition, Minger said police are investigating fliers, e-mail and voice mail containing threats against freshman Kent Harvey, whose run-in with Knight led to the coach's dismissal. The student and his family have changed their telephone numbers and e-mail addresses.
Police said no one has been arrested in connection with any of the threats. Fewer than 10 people were arrested Sunday mostly on disorderly conduct charges when students marched in protest of Knight's firing.
The Hall of Fame coach was dismissed after 29 years at the school for what the university called a "pattern of unacceptable behavior." He was accused of grabbing Harvey's arm and berating him for addressing him as "Knight."
Minger said he has seen more damage on campus following basketball championships and some football victories.
"I was here for the Vietnam riots in 1972," he said. "To me, Sunday night was fairly orderly, although a small percentage of participants caused minor damage."
Minger did not discuss the investigations but said they were being handled "very seriously."
Knight addressed about 6,000 students Wednesday night and told them to stay under control.
"Let that kid (Harvey) be a student and let him get on with life. ... This thing, believe me, had happened to me long before that situation took place. That kid is not responsible for my not coaching at Indiana."
But Peg Brand said Thursday the threats have continued despite Knight's call for calm. She said she came forward after some of her students expressed fear.
"My friends and people I love are being individually singled out and targeted in a malicious way," she said.
Her voice mail was not activated Friday, and she did not immediately respond to an e-mail request for comment.
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