Understaffed police departments and concerns over public safety are spurring greater use of private security guards. But they aren't a perfect substitute.

Funding was restored in July to a program that provided shifts of unarmed security guards ... in the majority of these buildings, security guards are on duty for one eight-hour shift per day.

The unarmed guards will patrol the stations and respond to security threats and emergencies. They'll alert the police if necessary. "If something does arise where we need an appropriate response ...