The brother-in-law of Oscar-winning actress Jennifer Hudson killed three of her relatives - with a gun stolen from one of the victims - because he was angry his estranged wife, the star's sister, was dating another man, prosecutors alleged.
William Balfour appeared in a Chicago court for the first time in connection with the deaths and was denied bond.
His attorney said authorities have no forensic evidence linking Balfour to the killings, but prosecutors said witness statements and the suspect's own lies and threats helped lead them to him.
Balfour was charged with murder on Tuesday after being held for weeks on a parole violation.
The slightly built man, wearing a yellow jump suit, stood quietly as prosecutor LuAnn Snow described how he allegedly killed his seven-year-old stepson, Julian King, Hudson's mother, Darnell Hudson Donerson, and Hudson's brother, Jason Hudson.
Ms Snow said Balfour had been at the Hudsons' South Side home early on October 24 and confronted his estranged wife, Julia Hudson, about a birthday present he believed she had received from a boyfriend.
Balfour, Ms Snow said, also had shown up to Julia Hudson's workplace earlier in the month to confront her about dating another man.
"He told her at the time that her family would suffer if she saw other men," Ms Snow said after the hearing.
Balfour threatened Julia Hudson again that morning at the home, Ms Snow said, adding that Julia Hudson did not take the threat seriously because he "had not followed through on any of those threats" before.
The prosecutor said, the gun belonged to Jason Hudson and Balfour allegedly stole it during the summer. "Several people observed (the) defendant with the gun in the late summer of 2008," Ms Snow said.