Chief Myers said he worried that if law-abiding citizens stopped going out at night or visiting parks, the city’s deserted open spaces could attract more criminals.

One of most influential policing concepts in recent years has been the “broken windows” theory, which holds that addressing minor crimes and signs of disorder can head off bigger problems down the road. Colorado Springs is taking a different tack.

To close a budget gap — the city’s voters, many of whom favor smaller government, turned down a property tax increase in November, and a taxpayer’s bill of rights makes it hard for city officials to raise taxes — Colorado Springs has stopped collecting trash in its parks, stopped watering many medians on its roads and reduced its police force.

The sprawling city of roughly 400,000 at the foot of Pike’s Peak — which covers 194 square miles — made national news when it auctioned off its police helicopters. But less-heralded police cuts could have more impact: the force, which had 687 officers two years ago, is down to 643 and dropping. At any given time, the department estimates that there is a 23 percent chance that all units will be busy.

So it has reduced the number of detectives who investigate property crimes, cut the number of officers assigned to the schools and eliminated units that tracked juvenile offenders and caught fugitives. Officers no longer respond to the scene of most burglaries, at least if they are not in progress.

At the same time, the city joined others — from Fitchburg, Mass., to Santa Rosa, Calif., and began turning off streetlights. Several recent studies have suggested that streetlights help reduce crime — something residents here say is obvious.

Natalie Bartling, a new mother, could not believe it when the light outside her home was shut off in April. Ms. Bartling, 38, had successfully lobbied for the light five years ago after a wave of vandalism and petty thefts hit her middle-class block. So this time she called daily until the city agreed to turn it back on.

“When it got shut off, it was like missing something,” she said on a recent night, standing under its glow. “Part of your life.”