Oscar-winning actress Jennifer Hudson wiped away silent tears as a jury read the verdict she had awaited for over three years, finding her brother-in-law guilty of killing her mother, brother and young nephew.
William Balfour, the estranged husband of Hudson's sister Julia, was accused of killing his in-laws in October 2008 and then hiding his stepson's body to try to cover his crimes.
It was three days before the boy's desperate mother and aunt learned that he was also dead and not just held captive.
"This was a vicious, cold-blooded, inhumane execution of three people, including a seven-year-old boy who just happened to be home from school,'' State's Attorney Anita Alvarez told reporters.
"We are very, very happy with the verdict.''
Jennifer Hudson declined to speak to reporters after the verdict, but Alvarez said the entire family was relieved and appreciative.
"She was very emotional about the verdict and so was her sister and the rest of the family _ emotional but relieved,'' Alvarez said.
"This verdict cannot bring back their loved ones but we hope it brings them some closure.''
Prosecutors said Balfour acted out of an obsessive jealousy when he shot his way into Hudson's childhood home and killed everyone inside after getting into yet another argument with his estranged wife.
Julia Hudson was at work at the time of the shooting and came home to find her mother, Darnell Donerson, 57, dead on the floor in her nightgown.
She was so distressed that she ran outside to call police and did not realize immediately that her brother, Jason Hudson, 29, was dead in his bed wearing nothing but a pair of green underwear, or that her son was gone without a trace.
Julian King was eventually found hidden under a shower curtain on the back floor of his uncle's stolen sport utility vehicle, which had been parked across town.
The murders in Chicago's South Side upended Hudson's life less than two years after the one-time American Idol contestant collected a best supporting actress Oscar for her role in Dreamgirls.
The two-week trial opened a window onto the troubled Englewood neighbourhood where Hudson was raised and which her family never left.
Hudson, choking back tears, had testified in April how no one in her family wanted her sister to marry Balfour.
"We didn't like the way he treated her, and I didn't like the way he treated my nephew,'' the 30-year-old singer and actress told the Chicago court.
Many of the witnesses had criminal records and several testified about how Hudson's brother was a small-time drug dealer.
Public defender Amy Thompson - who insisted at trial that police failed to look into Jason Hudson's drug connections and instead decided Balfour was the only suspect _ said she planned to appeal the verdict.
"William Balfour is innocent of these murders and we're hopeful that the appeals court will look at this with a very careful eye,'' Thompson told reporters.
"My client is a very stoic young man. He doesn't emote much. He's hopeful in the appeal. This was a very hard blow for him.''
Balfour faces a mandatory minimum sentence of life in prison.
Hudson, who released her second studio album I Remember Me in March 2011, and sang I Will Always Love You in memory of the late Whitney Houston at this year's Grammy awards, attended the entire trial.
She was accompanied to court by her longtime partner, professional wrestler David Otunga, her sister and other relatives.