The "gang book" also found that two-thirds of murders in the Chicago area have gang ties. And there could be as many as 150,000 gang members in the Chicago area.
The summit on the campus of Loyola University is closed to the public. But former Chicago police superintendent Jody Weis, who now heads up the commission, will hold a news conference Friday afternoon.
The "Gang Book" estimates there are 73 gangs active in Chicago.
The book includes gang profiles, Chicago gang maps, gangs in the suburbs and current and past gang trends.
Chicago Crime Commission President Jody Weis (WEES) says gangs have splintered into factions following the forced closing of public housing. That splintering has given rise to teenagers gaining authority in their neighborhoods. That differs from older gang leadership structures.
Weis is a former FBI agent who took over as Chicago's top cop in 2008. He resigned last year when his contract came to an end.
The Associated Press contributed to this report.