Updated 05/09/12 – 9:42 p.m.

CHICAGO (CBS) — Jurors began deliberating Wednesday in the murder trial of the man accused of killing Oscar-winner Jennifer Hudson’s family, but were sequestered for the night after more than 4 1/2 hours of deliberations, and will go back to work on Thursday.

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Jurors got the case at about 4:45 p.m. Wednesday, after prosecutors and defense attorneys wrapped up closing arguments, with the defense claiming prosecutors didn’t prove their case, and the state arguing there was “overwhelming” evidence of the defendant’s guilt.

Shortly after 9:30 p.m., the judge announced the jury was being sequestered for the night and would be told to resume deliberations at 9:30 a.m. Thursday.

CBS 2’s Dana Kozlov reports William Balfour, Hudson’s former brother-in-law, is charged with killing her mother, brother and nephew three-and-a-half years ago. Prosecutors have claimed Balfour, 30, shot the victims in a jealous rage, believing his then-estranged wife, Julia Hudson, was seeing another man.

According to the prosecution, Balfour killed 57-year-old Darnell Donerson in the Hudson family’s living room on Oct. 24, 2008, and then killed 29-year-old Jason Hudson as he lay in bed.

Balfor then allegedly kidnapped 7-year-old Julian King – Julia’s son – and shot him in the head in the back seat of Jason Hudson’s SUV, which he stole, then abandoned on the West Side. Julian’s body was found three days after the murders.

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Both sides took much longer than expected to argue their cases on Wednesday afternoon.

The prosecution went right for the jury’s emotional jugular, first showing photos of the three victims in life, and moving right to their autopsy pictures.

Jennifer Hudson cried and slumped over for most of the state’s closing arguments, comforted by her fiancée, while a stone-faced Balfour looked on.

Assistant Cook County State’s Attorney Jennifer Bagby wasted no time during her closing argument, saying “Today is the day to hold him responsible for shooting Julian King, Jason Hudson and Darnell Donerson.”

Bagby spoke firmly, insisting to the jury that Balfour followed through on repeated threats to kill Julia Hudson’s family.

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“He went into the house with Jason Hudson’s gun for one reason, and one reason only, to carry out that threat,” she told jurors.

But Balfour’s defense attorney, Amy Thompson, called much of the prosecution’s case a story full of holes. She insisted those holes created reasonable doubt about Balfour’s guilt.

“The one consistency in this case is that every piece of DNA evidence absolutely excludes William Balfour,” Thompson told the jury. “The one person in Chicago we know didn’t do it is him.”

CBS 2 Legal Analyst Irv Miller said, “You had very, very good lawyers on both sides of this. Both the prosecutors and the defense attorneys are outstanding lawyers, and that showed during these closing arguments. The jurors paid attention, now the jurors have to make a decision, and the biggest decision, they have to judge the credibility of witnesses; who’s telling the truth and who’s not?”

Bagby spent an hour outlining the state’s triple-murder case against Balfour, saying there was an overwhelming amount of circumstantial evidence to prove his guilt.

“You don’t just have witness testimony in this case,” she said. “There is physical evidence in this case … keep it clear … just because something wasn’t there doesn’t mean he wasn’t there.”

Bagby then reviewed evidence, including cell phone pings that put Balfour near the Hudson house the morning of the murders, and firearms evidence that showed all three victims were killed with Jason Hudson’s gun – the same one several witnesses said Balfour had.

She also pointed to the fact Jason Hudson’s SUV key was found in Balfour’s pocket when he was taken into custody on the day of the murders.

But Thompson came out equally strong, and equally passionate during her closing. She raised questions about why that key was not initially inventoried as evidence, or why police waited three years to test it.

Thompson also attempted to discredit prosecution witnesses and hammered on the fact that there is no DNA or fingerprint evidence directly linking Balfour to the murders.

“They weren’t trying to investigate a case,” Thompson said. “They were trying to convict a pre-chosen defendant … and unfortunately for William Balfour, an innocent one.”

The defense has said Balfour had nothing to do with the murders and suggested they were instead linked to Jason Hudson’s own alleged drug dealing.

Balfour has pleaded not guilty to three counts of first-degree murder. He is also charged with home invasion, aggravated kidnapping, residential burglary, and possession of a stolen motor vehicle. If convicted on all counts, he would face a mandatory life sentence.

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Jurors will deliberate as late as 9 p.m. on Wednesday. If a verdict is not reached by then, they might be sequestered for the night, before they resume deliberating Thursday morning.