CHICAGO – Hundreds of Chicago police officers are hitting the streets on overtime every night in dangerous neighborhoods, the latest tactic by Mayor Rahm Emanuel's administration to reduce killings in a city dogged by its homicide rate and heartbreaking stories about honor students and small children caught in the crossfire.

The decision by Chicago Police Superintendent Garry McCarthy last month to put small armies of officers working overtime in specific "hot zones" corresponds with a notable drop in homicides in the nation's third-largest city in February and March. But the latest "Violence Reduction Initiative" raises concerns about whether the policy is sustainable for the financially struggling city and whether it could further strain officers working long hours at a stressful and dangerous job.

If it continues, the tactic would cost millions of dollars each month — putting the one initiative on pace to exceed the department's entire overtime budget by fall.