William Balfour, a suspect in the tragic murder case of Academy Award-winning actress Jennifer Hudson's mother and brother has been taken into custody, but his missing step-son, Julian King, the son of his estranged wife and Jennifer’s sister, Julia, was not with him, the Chicago Tribune reported.

While an Amber Alert remains in effect for the 7-year old boy, who was in the house with his grandmother and uncle at the time of the shooting but was reported missing from the home by his mother, the FBI reportedly joined the police in the search for Jennifer's nephew. Police believe the stepfather may be behind his disappearance.

The FBI was called into the search because of the possibility that the boy was taken across state lines. Law enforcement sources told the newspaper that they were hoping to find Julian when they picked up Balfour but that the boy was not with him.
According to state records, Balfour, 27, was currently on parole after serving time for attempted murder and vehicular hijacking. He and Julia had been married for about two years, though they were apparently separated and headed for divorce.

The mother and brother of "American Idol" contestant Jennifer Hudson were found dead in their mother's house on the South Side of Chicago on Friday afternoon from multiple gunshot wounds. According to TMZ, the victims were found by Jennifer’s cousin who lives close to the house around 3:00 pm Chicago time.

The police confirmed that Hudson’s mother, Darnell Hudson Donerson, 57, was found shot in the head in the living room, and her 29-year-old son Jason Hudson, was shot to death in the chest in a bedroom. Police said there appeared to be defensive wounds on one of the victims, suggesting at least one of the shootings involved domestic violence. No signs of forced entry were registered at the house.

Balfour, who has been childhood friends with the Hudson family, reportedly has records that show he previously pleaded guilty in 1999 to attempted murder and vehicular hijacking, in which he served seven years behind bars, before being released in 2006.

Defending her son, Balfour's mother told the Chicago Tribune that her son and Julia were separated and that Donerson had thrown him out of the family home last winter. She also pleaded for the return of the missing child.

"Whoever has Jennifer Hudson's nephew or Julia Balfour's son, please, I'm begging you, me and my family are begging you to return that son," Michelle Davis-Balfour told CNN affiliate WLS.