Updated

The man accused of killing Oscar winner Jennifer Hudson's mother, brother and 7-year-old nephew had threatened to kill members of the family at least two dozen times before the October 2008 slayings, a prosecutor said during a Friday hearing in Chicago.

Assistant State's Attorney James McKay said the threats began in February 2008, when James Balfour moved out of the family's house where he had been living with his wife, Hudson's sister Julia. The threats continued right up until the day the bodies were found, on Oct. 24, 2008.

"He said, 'If you ever leave me, I'm going to kill you, but I'm going to kill your family first,'" McKay said at the hearing. "'You will be the last to die.'"

Friday's hearing comes about a month before Balfour is scheduled to stand trial in the slayings. Prosecutors allege Balfour shot the family members because he was furious his wife was dating another man. Balfour has pleaded not guilty.

The killings in one of Chicago's most dangerous neighborhoods generated international headlines when the bodies of Hudson's mother and brother were found in the family's home and the boy's body was discovered in an SUV days later.

On the day of the killings, Julia Hudson noticed her estranged husband in an alley beside the home as she was getting ready to head to work and let him inside, McKay said.

The prosecutor said Balfour became enraged when he saw balloons that a new boyfriend had given her and he realized at that point that his marriage was "crumbling."

"All of this is boiling over and when he sees those balloons it's time to act," McKay said.

Julia Hudson worked as a bus driver, and Balfour made one of the threats in person when he got on her bus a month before the killings. He told his wife, "I'm thinking of taking Julian," said McKay, calling the words a clear threat to kidnap her son from a previous relationship.

Seven-year-old Julian King was one of those killed. The others were Hudson's mother, Darnell Donerson, 57, and brother, Jason Hudson, 29.

Police recovered a gun from bushes near the vehicle in which King's body was found and have linked it to the shootings.

Jennifer Hudson, who won an Academy Award for best supporting actress in 2007 for her role in "Dreamgirls," was in Chicago with her family about five days before the killings. She said she'd last been at the family home about two months earlier.

She told investigators she'd known Balfour since childhood and had advised her sister against marrying him. She said the family didn't find out about their 2006 marriage until months after it happened.