GPS Applications in Policing
Automatic Vehicle Location (AVL)
One of the most popular applications for GPS/GIS technology has
been fleet/resource management through AVL. These systems provide
efficiency of response and help ensure officer safety. AVL becomes
AVLN (Navigation) by comparing GPS data against known road
condition data. AVLN provides the officer with accurate information
concerning the best response route to an incident. It also gives
police officers and supervisors, information that allows the closest
patrol officers to be dispatched to a particular incident.
Should an police officer need immediate assistance, AVLN is
a safety net. It gives other officers or rescue personnel precise
information about the location of an officer in need of assistance.
This approach is also being applied to commercially available
navigation systems so that motorists will no longer have to guess
their location when requesting assistance from emergency response
personnel.
Critical Incident Mapping, Management, and Documentation
Critical incidents require the coordination of numerous emergency response resources over large distances and substantial lengths of time. It is necessary to keep documentation that will assist with incident management, and which will provide a record for subsequent debriefing, training, and court purposes. Time-critical GIS applications for critical incident management represent an effective way to manage and document incidents, especially when coupled with real time (GPS) AVL data. Advanced Transportation Management Systems (ATMS)
The Intelligent Transportation Systems concept relies heavily upon
technology to support the efficient use of multi-modal transportation
systems. Perhaps the most important of these transportation
systems, from the perspective of the first responder, is the road
system. Almost everything that the first responder does is tied to
the road system in some way. Most people associate law enforcement
with the prevention, reduction, and prosecution of criminal activity.
In fact, a large portion of local law enforcement resources are
involved in facilitating the movement of people and vehicles in a
safe manner. It is this part of the law enforcement mission that ties
it closely to transportation systems.
Advanced Transportation Management Systems (ATMS) are
heavily dependant upon GPS/GIS technology to provide data about
the road system. This information is translated into actions, by
traffic managers, which help to control and expedite the flow of
traffic. Law enforcement personnel use the same information,
relayed to them by traffic managers, to clear roadway blockages.
The same information, supplied to the average motorist, can help
them decide a course of action that will keep them from having to
wait in stalled traffic. This symbiotic relationship has the effect of
making the safest, most efficient use of the road system.
Mobile Computing and Field Reporting Systems
Wireless mobile computing provides the front-end data collection
capability that efficiently captures timely information for a variety
of investigative and analytical purposes, not the least of which are
GIS records management and analysis. Adding GPS data to the
DBMS means that the GIS applications will run more efficiently,
and with fewer spatial data translation errors.
Field reporting and data capture enables investigators to
assemble case files containing information that was previously next
to impossible to obtain and adequately correlate. With the use of
differential GPS (DGPS), investigators can precisely relate evidence
placement to crime scene reconstruction diagrams. The same applies
to accident investigation and reconstruction. By tying evidentiary
information into a GIS format, cases can be graphically displayed to
show the temporal and spatial relationships of crime reports, witness
statements, evidence, and crime scene drawings. GIS provides for a
variety of presentation formats. These presentation formats can
be easily and automatically displayed for court, training, and briefing
purposes.
Field captures of traffic citation and accident data supplies
law enforcement managers with valuable information to be used for
selective enforcement and resource management purposes. For
traffic managers and engineers, this type of data provides
information for traffic engineering or flow management needs.
Once again, a GPS component added to the data record, gives the
users valuable information about the exact location of particular
problems when used with the appropriate GIS application.
This crime and traffic data can be analyzed and accessed by
field units and investigators through the use of mobile computing.
Automated field reporting data is stored and collated in crime
databases. This data is, in turn, made available for a number of
investigative, informational, and analytical purposes. The advent
of GIS makes this information come alive in easy to comprehend
presentation formats. GPS data, tagged onto the DBMS, supplies
the key to effectively supporting the capabilities of GIS.
Monitoring probationers and parolees by GPS
Since probationers have tended to change addresses frequently, the
mapping system’s address verification function has helped probation
officers maintain contact with their clients. A map displaying
probationer addresses with overlays showing the locations of
potential risk areas (e.g., schools, high-crime areas) and service
providers (e.g., employment training and drug treatment facilities)
also has been helpful. Finally, supervisors have used the mapping
package to manage probation officers’ workloads by producing maps
showing the locations of each probation officer’s clients, color-coded
by the required level of supervision (i.e., minimum, regular, or intensive)
Continuous monitoring of the location of the probationers
can be done through a Global Positioning System. The cost of the
receivers, although decreasing, is certainly a factor. Electronic ankle
bracelets can been used to monitor probationers; typically, these
devices will trigger a telephone call to the probation officer when
the probationer moves more than a specified distance from a
location. Such devices could, in theory, also be used to detect
violations of restraining orders or other special conditions of
probation or parole (e.g., a person must keep a certain distance
away from schools or child care facilities)
Florida-based Pro Tech Monitoring (
http://www.ptm.com/) has developed a GPS-based tracking system, called the SMART
System, that combines Trimble’s miniature Lassen-SK8 GPS board
and cellular technology into a unit worn by the criminal offender. In
addition to the 3.5-ounce, tamper-proof ankle bracelet, the system
includes a portable tracking device (PTD) that is electronically
leashed to the ankle unit. The PTD contains the GPS receiver and
cellular communications.
Unlike conventional house arrest systems that only monitor
when offenders leave or return home, Pro Tech Monitoring’s SMART
system keeps track of offenders anywhere, at all times. The unit is
‘smart:’ it contains “rules of release” which stipulate where the
offender should be at all times. If an offender breaks these rules of
release, the system automatically warns the offender and then sends
a message to a control center if the problem is not immediately
corrected. Police departments in at least 16 states of United States
use SMART (Satellite Monitoring and Remote Tracking).
The SMART system is appealing because it uses existing
technology, transforming the traditional electronic ankle bracelet
from a monitoring device to a tracking device. It records where a
wearer of the bracelet goes and enables officers to monitor the
person’s movement via PC-based workstations and Internet-accessible
maps.
Here’s how SMART works
- Portable tracking device: For GPS to work, an offender must carry a GPS receiver, complete with a microprocessor and antennae, to record locations. The offender carries the device in a waist pack. The recorded data is fed to a data center or a monitoring station via a cellular transmission
when portable or via a phone line when the device is charging at the offender’s home. The microprocessor in the unit can be programmed to create inclusion zones (places the offender must be at certain times) and exclusion zones (places where the offender is not allowed). If either zone is violated, the receiver sends an alarm via pager to the monitoring station and the victim
- Electronic ankle bracelet: Equipped with a radio transmitter, this traditional monitoring device works in tandem with the GPS receiver, essentially acting as an electronic tether. The receiver constantly measures the signal strength in the ankle bracelet. Thus, if the receiver is left behind in the house while the offender goes to work, the receiver will set
off an alarm at the monitoring station. Both pieces of
equipment also have tamper-detection features to keep
offenders from trying to remove or dismantle them.
- Monitoring stations: The data collection center of the
operation requires only a PC workstation and Microsoft
Corp. Windows-based software designed by Pro Tech. When
SMART is in action, the screen shows maps ranging from
single streets to citywide zooms. “Blips” indicate where the
offender is. Staff members keep pagers and cell phones that
take violation calls from the GPS receiver.
- SMART surveillance system: Through a secure Internet
connection, a monitoring station can access and save
information to a Pro Tech-created database of national
maps, longitudinal and latitudinal points, maps of offenders’
movements and customized reports.