LOS ANGELES, California (X17online) - A friend of Jennifer Hudson claims they tried to warn the Academy Award winner's family about William Balfour, a "person of interest" in the shooting death's of Hudson's mother, brother and nephew, US Magazine reports.

Balfour is divorced from Hudson's sister Julia, reportedly got into an argument with the family one month ago a neighbor tells the magazine.

"Flex tried to start a fist fight with Jason, and James beat up Flex," the neighbor adds.

Shortly after, Flex began to threaten the family, saying "he would kill Julia and mess up everyone in the house," the source tells Us.

Many people in the neighborhood were aware the couple had "been having problems, but I never expected anything like this," neighbor Angela Russell admits to Us.

Balfour's mother insists her son "had nothing to do with" the shootings.

Balfour is currently being held on violation of parole stemming from an attempted murder conviction in 1999. The AP reports that he was arrested on June 19 for possession of crack cocaine, but his parole was not revoked after the arrest.

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