Jennifer Hudson
Jennifer Hudson took the stand on Monday in the trial of William Balfour, who is charged with murdering the singer's mother, brother and nephew. Reuters

The trial for the man accused of murdering Jennifer Hudson's family began this week. The American Idol finalist was the first witness to take the stand at the trial of her onetime brother-in-law William Balfour on Monday, the Associated Press reported.

Balfour, the estranged husband of the singer's sister, is on trial for allegedly killing Hudson's mother, brother, and nephew in 2008. The jury selection process was a challenge, with legal officials concerned about inadvertently picking jurors who might be sympathetic to the Oscar-winning actress and unconsciously bias the proceedings.

Hudson was very emotional and cried throughout her testimony, according to various media reports.

None of us wanted her to marry him, she said, referring to her sister, Julia, and Balfour, the AP reported.

Balfour's lawyer, public defender Amy Thompson, told the jury that the DNA found on the murder weapon, a gun, didn't match the defendant's DNA, the AP reported. Thompson also described Hudson's late brother, Jason, as a drug dealer who brought danger to his family, ABC reported.

Hudson's sister also took the stand and admitted that she was still having sexual relations with Balfour days before he allegedly murdered her family members, the AP reported. She also said that she never believed his threats to kill her family.

This is not a woman who is afraid of William Balfour, Thompson said, according to a Chicago Tribune report.

Trial proceedings will continue on Tuesday, with prosecutors expected to offer evidence that Balfour was present at the scene of the murders, the AP reported. He denied being present.