William Balfour, 30, is charged with the shooting deaths of the star's mother, brother and nephew in October 2008. Prosecutors argued Balfour -- the ex-husband of Hudson's sister, Julia -- killed her family because she left him and was seeing another man.
Reporters from the Chicago Tribune said via Twitter the photo with which prosecutors ended their argument depicted Julia's dead 7-year-old son, Julian King, grinning with his arms raised over his head. It was shown shortly before a break to prepare for the start of the defense's closing argument.
Prosecutors said witnesses, Balfour's statements to police and overwhelming circumstantial evidence, including cellphone records, "point to one place and one place only," the Tribune reporters said.
The lawyers noted Balfour is charged with home invasion, kidnapping, burglary and possession of a stolen vehicle, which could help qualify him for a life sentence in prison without parole, if he is convicted.
Balfour is accused of kidnapping Julian after shooting and killing the boy's mother- and brother-in-law, and then stealing his brother-in-law's sport utility vehicle, shooting the child and leaving his body in the vehicle where it was discovered two days later.
The Chicago Sun-Times reported Assistant Public Defender Amy Thompson said in her closing arguments authorities didn't consider any other suspects than Balfour and lacked evidence to prove he committed the crimes.
Thompson called into question Balfour's possible motive, saying Julia continued to have sex with Balfour after she alleged he threatened to kill her family, so she couldn't have been that afraid of him.
Balfour's attorney said victim Jason Hudson, the brother of Jennifer and Julia, was a drug dealer with enemies who could have killed him, his mom and his nephew.
"The one constant in this case is that every piece of DNA evidence absolutely excludes William Balfour," the Sun-Times quoted Thompson as saying, adding the gun used in the triple homicide had DNA on it linked to two other people. "They have evidence they ignore. There is DNA on this gun, it's just not his. There's not no DNA on his gun. There's just not William Balfour's on this gun. ... This wasn't a whodunit. They weren't trying to figure this out. They had their man, they spread it across the news. They were just trying to prove it by building a case any way they could."
Thompson concluded by describing her client "as an innocent man."
"They have an obligation to find the people who actually did this. Not just for William Balfour, but for the Hudson family," she said.