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William "Flex" Balfour, the estranged brother-in-law of Jennifer Hudson, has been arrested in connection with the murders of the singer's mother, brother and 7-year-old nephew.
Though there have not yet been any formal charges, Balfour was transferred from an Illinois state prison -- where he was being held on a parole violation -- back into police custody.
A neighbor told Us Weekly that Balfour and Jen's sister Julia had screaming matches and had "been having problems, but I never expected anything like this."
We'll keep you posted on what happens next with the arrest. In the meantime, get more scoop here: