Updated

Chicago police are solving homicides at a far lower rate than their counterparts in some other major cities, which may reflect how hard it is for detectives to crack the culture of silence surrounding the violence committed by the city's street gangs.

Of the 432 homicides committed between January 1 and August 16 of this year, the department has solved 92, or 21 percent of them, the Chicago Tribune reported.

When homicides committed in all years are added in, the department says the clearance rate is about 30 percent. But even that figure is lower than the 49 percent clearance rate in Philadelphia and 56 percent clearance rate in Houston, which ranks just behind Chicago in terms of population size.

Experts say one reason so few are solved is that, as police have long said, so many are related to gangs in the poor neighborhoods where most of the shootings occur. They say witnesses who live in these neighborhoods are afraid to come forward out of fear of retaliation and a gang culture in which gang members have been historically unwilling to cooperate with police.

Others say that manpower on the police force may be a factor.

"Homicides have gone up and the number of shootings has gone up; and the number of detectives has gone down," said Fraternal Order of Police President Dean Angelo.

In fact, the FOP says the number of detectives has dwindled from 1,151 in 2009 to 863 as of July. Not only that, the union says the number of evidence technicians, whose job is crucial to investigations, has dropped from 113 to 84 over that span.

This comes amid a sharp spike in the number of homicides and shootings this year.