Welcome to the inaugural edition of It’s in the Details, a short newsletter intended to provide helpful information for those in the litigation industry who deal with forensic engineering experts and their work.
“Why does my forensic expert bug me to get original files of digital photos?”
In this edition, we touch upon a topic common to almost every forensic analysis: digital photos supplied by third parties.
Digital photos can serve as key documentation of incident scene evidence. From tire marks at a crash site to fracture surfaces on a failed structure to burn patterns at a fire scene, digital imagery is often some of the most important documentation we forensic engineers are given.
However, what many people don't know is that the quality and content of digital images can vary greatly, depending on how they are saved, transmitted, and reproduced. The aspects of digital images we’d like to maintain include:
- Resolution – the “dimensions” of the image, in pixels. More resolution equals better image quality, giving us the ability to see finer details in the photo.
- Metadata – this is data “hidden” within the file that can give us important technical information, such as the date and time the photo was taken, the type of camera used to take the photo, the camera settings, and in some cases, even the GPS location of where the photo was taken!
- File format – this is the “standard” to which the digital image file was saved. Most cameras save their photo files in a JPG (“jay-peg”) format. Later changing the file format (into a PDF, for example) can potentially alter the quality of the image or remove its metadata entirely.
So you can see how important it is to maintain the integrity of the original image files you provide your forensic expert. To do that, here are some helpful guidelines:
- DON’T have someone “text” the images off their smart phone. Instead, the phone owner can (1) use a file sharing service, like Dropbox, OneDrive, WeTransfer, etc. to transfer the files from the phone; (2) connect the phone to a computer, copy (“drag”) the images off and then use a file sharing service to distribute; (3) email the images one or two or three at a time at full resolution.
- DON’T use the option some smart phones give to “reduce image size for emailing”. Instead, send just a few at a time via email, at full resolution.
- DON’T change the format of the original file.
- DON’T rename the file. This helps maintain the file’s forensic integrity.
By sticking to the above rules of thumb, you will be greatly helping your forensic expert with their job all while maintaining the condition of what could be critical evidence for your case.
Thanks for reading, and feel free to reach out to us with any technical questions you might have about this or other topics related to forensic engineering.