Authorities didn’t identify the body of a young black boy found in the SUV Monday. But police Cmdr. Wayne Gulliford said the license plate on the SUV found Monday matched the one sought in an Amber Alert issued after the singer’s mother and brother were found shot to death at home Friday.

Julian King, 7, hasn’t been seen since the killings. He lives in the home where the shootings took place.

His his Oscar-winning aunt offered $100,000 Sunday for information leading to his safe return. Julian is the son of Jennifer Hudson’s sister, Julia Hudson.

The Amber Alert listed William Balfour, the estranged husband of Julia Hudson, as a suspect in a “double homicide investigation.” He is not the boy’s father and has not been charged in the slayings.

Police said they did not have a motive for the killings but called the case “domestic related.”

Balfour, 27, was taken into custody Friday by Chicago police for questioning in the killings. On Sunday, he was transferred to the Illinois Department of Corrections “based on his active parole violation unrelated to this investigation.”

Records from the Corrections Department show Balfour is on parole and spent nearly seven years in prison for attempted murder, vehicular hijacking and possessing a stolen vehicle.

Corrections spokeswoman Januari Smith said Balfour would probably remain in state custody until the Illinois Prisoner Review Board looked at his case. She would not say where Balfour was being held.

It was unclear whether Balfour had an attorney Sunday, but his mother, Michele Balfour, has denied he was involved the killings or in Julian’s disappearance.

Hudson, who won an Academy Award in 2007 for her role in “Dreamgirls,” was in Chicago during the weekend. The medical examiner’s office confirmed Hudson, 27, identified the bodies of her mother, Darnell Donerson, 57, and 29-year-old brother, Jason Hudson. The deaths were ruled homicides.

Hudson appealed to the public for help, offering the reward and asking any information be given to Chicago police.

“Jennifer and her family appreciate the enormous amount of love, support and prayers they have received while she and her family try to cope with this tragedy and continue the search for Julian,” said a statement from her publicist.