Balfour, who was paroled two years ago after serving seven years in jail for attempted murder and other crimes, has been referred to as Julia Hudson's estranged husband by the Chicago Tribune and Chicago Sun-Times.
His mother said he is innocent and had nothing to do with the tragic events.
"This is not my son that did this," a very distraught Michelle Davis Balfour said. "You cannot say my child did this to that girl. He loved Julia. He loved Julia's mother. My God, he put that girl's mother before me."
Mourners have showed an outpouring of emotion outside the family house, where the red Toyota that Jennifer Hudson bought for her mother sits with a birthday card for the missing Julian in the backseat.
Neighbors said Jennifer Hudson had urged her mother to leave the high-crime neighborhood but, after having lived there for decades, her mom told her it was her home.
The tragic events come just before Jennifer Hudson was scheduled to embark on a world tour today to promote her self-titled debut album with its chart-topping single, "Spotlight."
Hudson, whose star had been on the rise after she was ousted on season 3 of "American Idol," was featured in the summer blockbuster "Sex and the City" and stars in the film "The Secret Life of Bees."
In 2007, she hit superstardom with her debut film role in "Dreamgirls," earning a best supporting actress Academy Award for her role as rising singer turned down-and-out single mother Efie White -- a role Hudson said she always wanted to play.
The singer also recently announced her engagement to David Otunga, best known for his stint on VH1's reality show "I Love New York."
The Associated Press contributed to this report.