Jennifer Hudson

Jennifer Hudson's estranged brother-in-law, William Balfour, was formally charged Tuesday with three counts of first degree murder and one count of home invasion in the deaths of the actress' mother, brother and 7-year-old nephew, The Associated Press reports.

Although he has not confessed to the triple homicide, Chicago Police Superintendent Jody Weis said he is "confident in the evidence" linking Balfour, who was arrested Monday, to the killings.

Prior to his arrest, Balfour, 27, was only identified as a "person of interest" in the case and was held in custody on a parole violation.

Balfour is the estranged husband of Hudson's sister, Julia.

Darnell Donerson, 57, Jason Hudson, 29, were found shot to death Oct. 24 in Donerson's home, while the body of Julia's son, Julian King, was found three days later in the backseat of an abandoned SUV.

Jennifer Hudson, who took to her MySpace to thank fans for their support, declined to comment on Balfour's arrest, but Deputy Superintendent Steve Peterson said the family was "relieved and happy that the Chicago Police Department would bring this case to a successful conclusion."