The Oscar-winning actress is due to attend court on Monday, and may be called as a witness during the trial, which is expected to last at least one month.

William Balfour is charged with three counts of first-degree murder in the October 24, 2008 slayings.

He is accused of fatally shooting Hudson's mother, Darnell Donerson; her brother, Jason Hudson; and her seven-year-old nephew, Julian King. Donerson and Jason Hudson were found shot to death inside of Donerson's Chicago home.

King was found shot inside of an SUV three days after the crime. Balfour is the estranged husband of Hudson's sister, Julia.

Hudson first earned fame as a contestant on the third season of "American Idol," where she came in seventh place. She made her film debut in 2006's "Dreamgirls," for which she won an Oscar for best supporting actress.