Google Earth allows you to orient your audience to a physical location by zooming in from outer space to a three dimensional street view of the incident scene in your case. It is free. To use it live, you must be connected via a wifi signal or a cell signal. For most major cities, Google has created a "street view" option, that allows you to literally move your audience down the street from the pedestrian or driver perspective.
Maps App on iPad
This is an app that comes standard on the iPad. It has both a 2D and 3D view, and also allows you to zoom in on a scene. Like Google Earth, make sure you are connected by wifi or cell signal in order to use it live. You can also take a screen shot of the image and drop it into a PowerPoint slide.