Chicago police struggle to solve violence, earn trust of community

CHICAGO - After 74 people were shot over one of the city's most violent weekends in more than two years, Chicago police said they would flood the city's crime-wracked neighborhoods with hundreds more cops while acknowledging that no arrests for those shootings had been made as of late Tuesday.

A day earlier, Mayor Rahm Emanuel and police Superintendent Eddie Johnson had pleaded with the community to come forward with information to hold people accountable for the carnage, including 12 fatalities.

"You all know who these individuals are," a frustrated Johnson said at one point.

"If you know who did this, be a neighbor, speak up," Emanuel added.

But the Police Department's struggle to solve violent crime or earn the cooperation of residents is not a new problem