This spring, as lawmakers in the Illinois State Senate debated a bill that would restrict local programs known as crime-free housing, hundreds of witnesses showed up to share their views on the proposed changes.

City officials and police chiefs argued that ordinances governing the programs, which can require landlords to evict renters who have had contact with law enforcement, should stay as they are. Aggressive ordinances are needed, they said, to help the police oust drug dealers who set up shop in apartment buildings, and to compel landlords to deal with problems at their properties.

Housing advocates and renters spoke in support of major changes, pointing to multiple instances of discriminatory and unlawful enforcement. Landlords also pleaded for further regulation, telling senators they had no interest in acting as the enforcement arm of the police.

It is a debate that has intensified over the past three decades as the number of crime-free housing programs spread from a handful of early adopters to more than 2,000 municipalities across 42 states.

An investigation by The New York Times and The Illinois Answers Project found that in recent years, hundreds of people have been evicted in Illinois, many of them over minor infractions that occurred nowhere near their homes. Sometimes people were threatened with eviction after they called 911 for help.