Police took William Balfour into custody Friday evening for an alleged role in the double murder of the mother and brother of entertainer Jennifer Hudson.Balfour, an ex-con on parole after serving time for attempted murder, was taken to a Chicago area precinct close to 10:00 pm Friday, but the search for a missing 7 year old relative continued into the night.Additionally, reports say that Balfour has not been cooperating with authorities in their search for the child Julian King.William Balfour, the prime suspect in the murder, is the husband of Hudson’s sister. He is not believed to be the child’s father. Balfour has been considered armed and dangerous, police said. Earlier in the night, police charged that Balfour was driving a white Chevy Suburban SUV with Illinois license plate X584859 or a green Chrysler Concord sedan with a damaged left front headlight and body damage along the left side with temporary tags 332K823.Chigago authorities say the child is wearing a tan jersey with the number 5 on it and tan slacks. They have also issued an Amber Alert for the 7-year-old King.The mother and brother of Academy Award-winning actress Jennifer Hudson were found shot to death today (October 24) in a Southside Chicago home.The family’s church reports that the victims were discovered thisafternoon by a cousin at 2:44 PM.Hudson’s mother Darnell Hudson Donerson, 57, succumbed to a gunshot to the head while brother Jason fell victim to a chest wound.Based on early evidence, police have ruled the crime a domestic dispute. Hudson rose to prominence during the 2004 season of popular television show “American Idol.” She later won an Oscar for Best Supporting Actress in the musical vehicle “Dreamgirls.”Her self-titled album Jennifer Hudson was released in early OctoberShe is next set to appear in the crime drama “Winged Creature” with Forest Whitaker, Guy Pearce, Kate Beckinsale, and her Bees co-star Dakota Fanning.AllHipHop.com will post more on this story as it develops.Additional Reporting by Tai Saint-Louis