Jackson, who held the seat for nearly 17 years, resigned from the U.S. House last month, citing his battle with bipolar disorder.
Among the Democratic candidates hoping to replace him are state Sen. Donne Trotter, who was recently arrested for carrying a gun into Chicago's O'Hare International Airport, and former U.S. Rep. Debbie Halvorson, who lost a primary challenge to Jackson earlier this year.
Officials didn't ask Trotter about the gun charge during the interviews conducted in public Saturday. However, Trotter was asked to explain the circumstances surrounding the incident and confirm his next court date during closed-session caucusing later in the day, Storman said. Trotter maintains he forgot the gun was in the bag when he packed for his flight.
Veteran Democratic consultant Delmarie Cobb, who sat in on the sessions, said she thought an open primary was a better outcome than endorsing a candidate facing a felony charge and risking embarrassment if his legal troubles worsen. With the deep economic troubles facing the district, it was better to fully open the choice to voters, said Cobb, who worked on the campaign that first got Jackson elected in 1995.
"That way it looks like it's about the voters making the final decision and not about party favoritism," she said.
Jackson resigned last month, weeks after easily winning re-election despite not campaigning beyond a robocall or being seen publicly in months. Jackson, the son of civil rights leader Rev. Jesse Jackson, took medical leave in June for treatment of bipolar disorder. His attorneys have also said they are cooperating with federal authorities on an investigation; they have not given details on what it involves.
Jackson's wife, Alderman Sandi Jackson, did not appear at Saturday's meeting and designated Zucarelli to cast her vote.
Officials would not provide a breakdown of the slating committee's voting, but Trotter was clearly a front-runner. He had the backing of Zucarelli, who had the most influence in the process. Each member's vote was weighted based on how many votes were cast in that official's ward or township in the last election.
Trotter's question-and-answer session before the committee was also twice as long as others, and he got applause as he left.
Trotter was arrested Dec. 5 when Transportation Security Administration officers discovered an unloaded .25-caliber Beretta handgun and ammunition in a garment bag during routine X-ray screening. Trotter's attorney says he has the gun for his separate work with a security firm.
Other candidates include Chicago Alderman Anthony Beale, state Sen. Toi Hutchinson, former state Rep. Robin Kelly and former U.S. Rep. Mel Reynolds, whose record includes convictions for fraud and having sex with a minor. Reynolds has said he believes voters will forgive his mistakes.
Republican James Taylor, publisher of the City News in Kankakee, has also announced plans to run.