Chicago ? It was the cradle of Jennifer Hudson’s greatest triumphs. It’s now the scene of her darkest hour.

The Oscar-winning actress and singer has often credited her rise to fame to her upbringing in the impoverished neighborhood on Chicago’s South Side where she went to grade school and sang in church.

At that church, her sister pleaded for the safe return of her 7-year-old son, Julian, on Saturday, a day after the siblings’ mother and brother were found shot to death at the family home in the Englewood neighborhood.

“I don’t care who you are, just let the baby go,” Julia Hudson said to a crowd from the podium of the Pleasant Gift Missionary Baptist Church with the boy’s father, Greg King, at her side.

“I know he’s out there,” she pleaded. “Just let him go. Put him on the side of the street. He’ll sit there. Somebody will see him. He’ll probably cry until somebody comes along.”

Authorities were holding a suspect with ties to the family, but no one had been charged Saturday. Law enforcement sources told the Chicago Tribune and Chicago Sun-Times that William Balfour was in custody, and the man’s mother said he is Julia Hudson’s estranged husband.

Julia Hudson did not address her relationship to Balfour, who was named in an Amber Alert issued after Julian’s disappearance. An alert remained in effect Saturday warning people to be on the lookout for Julian, possibly in a white Chevy Suburban.

Julia Hudson noted that her brother’s white truck was missing, but authorities did not say if it was the same vehicle mentioned in the Amber Alert or whether they were seeking additional suspects.

An autopsy Saturday showed Darnell Donerson, 57, and Jason Hudson, 29, died of gunshot wounds, according to the Cook County medical examiner’s office. Their deaths were ruled homicides.

Police said a family member entering Donerson’s South Side home Friday found a woman’s body on the living room floor. Officers later found Hudson shot in the bedroom. At least one of the victims suffered defensive wounds, said authorities, who described the shooting as domestic violence.

That same day, Julia Hudson reported Julian King missing. Chicago police spokeswoman Monique Bond, who declined to comment Saturday on a suspect, said no one had been charged. She has said that investigators were talking to “a number of people in custody.”

The Hudsons, who have insisted on not allowing 27-year-old Jennifer’s fame to alter their lives, lived in a three-story white house bookended by vacant lots. A grill and bottle of mustard stood on the lawn on Saturday, remnants of the barbecues they were known to throw on birthdays and holidays.

“They wouldn’t turn anyone away,” said Bob Israel, who lives in the neighborhood. “They didn’t want to change a bit.”

Hudson, who won an Academy Award for best supporting actress in 2007 for her role in “Dreamgirls,” talked of the influence of her family often.