I see the FCPD has a much more user friendly online crime map.
http://www.fairfaxcounty.gov/policeevents/
Police Event Data Disclaimer
The information provided on this site reflects actual calls for police service received by the Department of Public Safety Communications (911 call center) and entered into the computer-aided dispatch system.
Often these calls prove to be very different from the caller's original description or information. For instance, a resident calls to report a stranger outsite(sic) a neighbor's home and suspects a burglary is about to happen. The call for service is initially entered into the dispatch system as a possible burglary. Officers arrive, investigate and determine the "stranger" is a neighborhood youth who has broken a fence slat while trying to retrieve his ball.
A destruction would be entered on to the map of that street and neighborhood because this site reflects calls for police service as closed by the responding officer, not criminal incidents as perceived by callers. Further investigation by police detectives may also change the call for service incident type, which will not be captured on the map. Users of this site are cautioned to keep this in mind when accessing information appearing on this site.
The data represented on this site will give the user insight into what responding officers are determining, through preliminary investigation, is occurring on a given street or area. Therefore, it would not be appropriate or accurate to use this data as a measurement of incidents of crime in Fairfax County. Any use of this data for statistical purposes; for comparison of criminal activity over time; or for any commercial purposes is strictly prohibited.
Users will notice that some crimes do not appear on any maps and others are lumped together, such as sexual assaults. This is done to protect the victims.
The same is true for the location of calls for service on each street. While officers may be called to 2614 Example Street, the address will be displayed as 2600 Blk Example Street. The point on the map representing that call will be located a fraction of the distance between 2600 and 2699. The point displays the general location, not the actual address, of the call.
The Police Incident information displayed on these pages is originally entered in the County's computer aided dispatch system and then processed into format that allows the information to be shown on a map. This process is called geocoding. Generally incident information is available for viewing with 24 hours of the time an incident is reported.
The accuracy, completeness, timeliness, or correct sequencing of this information cannot be guaranteed and the Fairfax County Police Department cannot be held responsible for any error, omission, or result obtained from this information.