Jennifer Hudson Testifies on First Day of Family Murder Trial

Jennifer Hudson arrives at the 2011 American Music Awards held at Nokia Theatre L.A. LIVE on November 20, 2011. Steve Granitz/

Jennifer Hudson made a surprise appearance in Chicago on Monday — testifying on the stand, on the first day of the murder trial of estranged brother-in-law William Balfour, the accused killer of her mother, brother and 7-year-old nephew.

Although the singer and Oscar-winning actress, 30, had been expected to attend Monday's proceedings, prosecutors in the high-profile case surprised everyone by calling the star as the very first witness in Balfour's trial.

E! News reports that the Dreamgirls star emotionally recalled how she warned her sister, Julia Hudson, about becoming Balfour's wife.

"I told her over and over again to not marry him," said the star, who wore a conservative black suit and little makeup for the testimony. "We did not like how he treated her."

The estranged husband of the star's sister Julia, Balfour, 30, is accused of shooting and killing Hudson's 57-year-old mother Darnell Donaldson, 29-year-old brother Jason Hudson and 7-year-old nephew Julian King in October 2008.

Hudson appeared to be crying as she told the court she said she "talked to her [mother] every day."

According to lead prosecutor James McKay, Balfour told Julia a day before the killings, "If you ever leave me, I'm going to kill you, but I'm going to kill your family first."

Balfour has claimed innocence, and faces a mandatory life sentence if convicted.

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