A jury which included US talk show host Oprah Winfrey convicted a man of murder after two hours of deliberation.
Winfrey is planning to make a show about her experiences
Winfrey, 50, was paid $17.20 per day to sit on the Chicago jury which convicted Dion Coleman, 27, of first-degree murder. He could face a life sentence.
"It's a huge reality check, when your life intersects with others in this way, it is forever changed," Winfrey said outside the courtroom.
She is now planning to do a show about the trial with her fellow jurors.
Coleman was convicted for his role in the shooting of 23-year-old Walter Holley. He is due to be sentenced next month.
"The bigger story here for me is a man is dead, murdered, supposedly over $50, and that the real war is still going on in the inner-city streets every day," Winfrey said.
"Young black men killing each other. It was one of the saddest, saddest experiences I've ever had."
Winfrey's presence on the jury meant huge media coverage of the trial, which the presenter said was a distraction.
"This is not good for the victim's family," she said.
"This is not about Oprah Winfrey, the fact is a man has been murdered."
More than a dozen reporters and sketch artists filled the seats at the Cook County Criminal Courts building, while television cameras - which were barred from the actual courtroom - followed the presenter, thought to be a dollar billionaire, around its corridors.
Before she was chosen, Winfrey said she thought she was too opinionated to serve on the jury - but lawyers on both sides endorsed her presence.
Prosecutor Kathy Van Kampen said the attention surrounding Winfrey had no effect on the trial.
"She was accepted by both parties and we want fair, intelligent jurors on a jury, whether it's Miss Winfrey or anyone else," she said.
Juror Suzanne Goodman, who now plans to appear on the Oprah programme, said: "It was a lot of fun, it was like being on her show."