iWitness improves police crash scene mapping at night


WCSD image at night of smashed car in ravine


The Washington County (WI) Sheriff’s Department (WCSD) performed a 3D crash scene mapping using a Sony 5MP digital camera and iWitness. The incident involved a triple fatality. The car caught on fire in a ravine after crashing. Due to the crash being at night, WCSD utilized auxiliary lighting for their digital imaging, with the digital camera being tripod mounted. The crash evidence was later measured in the office using the iWitness close-range photogrammetry software system and thirty digital images acquired at the incident.


The crash scene evidence was spread over an area of 360 feet (approximately 110m). A WCSD detective measured the scene evidence using the iWitness ‘network stitching’ functionality to link two subset projects together over the scenes 360 foot distance. The accuracy of all measured objects was slightly better than one-tenth of a foot over the scene distance. 


Reportedly, the on-scene mapping time was cut by more than 50% using the iWitness photogrammetry approach, while 3D mapping accuracy is significantly improved over traditional methods used in the past by WCSD.