CHICAGO - Jurors returned to a Chicago courthouse Thursday to resume deliberating the case against Jennifer Hudson's former brother-in-law, who is accused of murdering three of the Oscar-winner's family members because her sister refused to take him back.

Judge Charles Burns ordered the jurors sequestered at a hotel for the night after they deliberated for four hours Wednesday following closing arguments in the case against William Balfour.

Balfour, 30, pleaded not guilty to three counts of first-degree murder in the October 2008 slayings. The former gang member faces a mandatory life prison sentence if he's convicted on all charges.

Prosecutors say Balfour murdered Hudson's mother, brother and 7-year-old nephew in an act of vengeance because his estranged wife at the time, Hudson's sister Julia Hudson, refused to reconcile with him.

With no surviving witnesses to call on to testify, prosecutors spent two weeks presenting a largely circumstantial case against Balfour.

His attorney, Amy Thompson, seized on that during her closing argument, saying prosecutors had failed to meet the burden of proof needed to convict Balfour of murdering the three victims. Defence attorneys suggested someone could have killed the three because of something related to Hudson's brother's alleged drug-dealing.

Prosecutors presented 11 days of testimony and called 83 witnesses, starting with Hudson, who was an "American Idol" finalist before winning the 2007 Academy Award for Best Supporting Actress for her role in the film adaptation of the musical, "Dreamgirls." Hudson told jurors about the last time she saw her three family members alive and spoke with distain about Balfour, whom she had known since eighth grade.

The defence called just two witnesses -- two detectives who had testified earlier -- in a bid to suggest investigators botched the triple-homicide investigation.

Prosecutors say Balfour shot Hudson's mother, Darnell Donerson, 57, in the living room of the Hudson family home on Chicago's South Side on Oct. 24, 2008, then shot Hudson's 29-year-old brother, Jason Hudson, in the head as he lay in bed.

Balfour then allegedly abducted Julia Hudson's son, Julian King, and shot him as he lay behind a front seat of an SUV. His body was found in the abandoned vehicle miles away after a three-day search.