Instant access to vital information: The role of GIS

GIS used successfully with leading public safety software will continue to offer the speed and performance needed to respond when seconds matter.

Simple map proves invaluable
     In the middle of a cold winter night, a 911 call is received at a communications center in an affluent suburb of Chicago, Illinois. A woman reports a suspicious vehicle parked across the street from her house. She tells the dispatcher that there appears to be multiple individuals entering and exiting the vehicle, and she reports having seen it circle the block several times. Officers are dispatched to the area.

     The dispatcher directs responding officers to the vehicle in an unfamiliar neighborhood with directions from their embedded GIS map within CAD. As the officers pull up to the suspicious vehicle, a person flees on foot and another is found hiding in the car. One of the responding officers pursues the fleeing individual and the other stays behind to wait for back-up.

     Back in the communications center, a second 911 call has come in from a resident who says he has been tied up in his basement by unknown subjects. The dispatcher instinctively looks to the CAD map to identify the exact location of this incident. He can clearly see that this second incident has taken place just around the block from the location of the suspicious vehicle. This discovery immediately changes the dynamic of the first call. The officers already at the scene are notified that the two incidents are likely related and to be on the lookout for more suspects in the area. Within minutes, the dispatcher is able to direct additional units to set up an effective perimeter in the area, which ultimately leads to the capture and arrest of several fleeing suspects.

     Access to GIS directly within CAD gives dispatchers an advantage when guiding officers in the field by offering a bigger picture of the surrounding area. In this case, the ability to see the layout of the land during an active incident enabled the dispatcher to recognize the connection between the two incidents. The officers at this scene were limited by their knowledge of that area, but the dispatcher, visualizing the entire scene through a CAD map, was able to provide enough information about the layout of the neighborhood to guide officers through unfamiliar terrain and aid in the set-up of a successful perimeter.

Growing cellular world and satellites
     A new challenge for emergency response personnel arose with the introduction and mainstream use of cellular phones. In 2000, nearly one-third of all 911 calls placed originated from cell phones, and the number continues to grow. It is critical for agencies to be able to locate a wireless caller who is unaware of or unable to describe his location.

     Mapping tools, including GPS and Phase II technology, have become a critical tool dispatchers rely on. These technologies enable the location of a cellular call to be found on a map with relative certainty. Using latitude and longitude information sent from a cellular phone, different technologies can locate the caller — in most cases, within meters of the actual location on the CAD map.

     Another important use of GPS location technology is the ability to provide real-time location of units on duty. Many agencies today have deployed AVL to allow incident managers to quickly see where units are in relation to incidents. GIS software also can provide estimated response times for units based on constraints such as speed limits, traffic patterns and rivers or bridges. This capability, coupled with in-car mapping technology, provides field personnel with a complete view of active incidents.

Making sense of large, unpopulated areas
     GIS and Phase II technology are particularly important in rural regions. Responsible for a New Mexico county that measures 5,600 square miles, a 911 center uses Phase II technology combined with geographical features to locate callers. Not long after the county adopted Phase II, the 911 center received a call for help from a man who had been assaulted and needed medical attention.

     The perpetrators had driven the victim through rural back roads and dropped him off in an unfamiliar location. Receiving latitude and longitude coordinates through Phase II technology, the dispatcher was able to determine his location within the county and quickly send help to the injured man. Without the use of GIS technology, the dispatcher would have spent precious time conducting a much longer examination of the victim's location, potentially allowing his condition to worsen.

  • Enhance your experience.

    Thank you for your regular readership of and visits to To continue viewing content on this site, please take a few moments to fill out the form below and register on this website.

    Registration is required to help ensure your access to featured content, and to maintain control of access to content that may be sensitive in nature to law enforcement.