Guide To Forensic Measurements and Photogrammetry

Crime scene investigators and forensic scientists use photography and measurements frequently in their work. Photographs are taken at nearly all stages of a crime scene investigation and they are also used in evidence comparison after the crime scene has been processed.

Crime scene measurement has been involved in forensic science since its beginnings. While the various methods used during crime scene investigations have changed over the years. The biggest impact on these methods has been from the technology itself. Technological systems and processes, as well as digital information, are vast and ever-changing.

crime scene measurement

Modernizing a field such as forensic science with the use of technology has a multitude of benefits. When discussing measurements and numbers within science, it is important to consider the concepts of accuracy and error.

Uncertainty, accuracy, and error have always been understood conceptually by forensic scientists due to the fact that expert witnesses would be asked to come up with degrees of certainty or accuracy of measurement during expert witness examination in court.

Due to the developments made by the field and the information more changes need to be made within forensic science. In addition to changes in forensic measurements and uncertainty, changes are occurring in other related areas of forensic science. 

As mentioned earlier, photogrammetry can be performed in order to take measurements. It is defined as the science or art of obtaining reliable measurements utilizing photographs and scales. In addition to taking measurements from images.

Photogrammetry encompasses methods of image measurement and interpretation in order to derive the shape and location of an object from one or more photographs of that object. In principle, photogrammetric methods can be applied in any situation where the object to be measured can be photographically recorded.

There are multiple different programs and techniques used to perform photogrammetry.

More simplified computer imaging programs are all relatively straightforward to use and install on any computer. The functions for photogrammetry of these programs can be learned easily and measurements of objects can be taken using a scale within the image.

Photogrammetry programs were more accurate for smaller objects. It was determined that certain measurement techniques may be beneficial when used with certain sizes of objects, but most methods of measurement were within the generally accepted 5% error rate. Because of this, all of the methods are acceptable as long as the limitations of each program or technique are considered