When it’s time to present forensic evidence to a judge and jury, prosecutors have traditionally relied on photographs and other visual methods to display evidence. Today, forensic anthropologists are embracing a much more detailed visual aid—with a little help from 3D Printing.
3D Printing for Forensic Evidence
In the case of homicide, there’s no better way to clearly present evidence to a jury than by showing them the actual bones in question, but that’s not considered best practice for an unbiased jury. “..presenting human remains can be disturbing for some individuals, which in turn could lead to prejudicing the jury,” said biological anthropologist David Errickson. There are also risks to the specimens. “…handing bones in courtroom environments could cause bone degradation, which could damage the very forensic evidence of interest.”
Forensic scientists have begun to get around these road blocks by scanning and 3D printing accurate bone samples to present to juries. While CT scanning and X-rays have already been used in the field for years, 3D printers have only recently become an affordable option. Already the printed bones have proved helpful in murder cases. UK prosecutors secured a murder conviction last May by 3D printing two humerus fragments, one found in a man’s house and the other from a suitcase found in a canal. They used software to demonstrate that the two fragments fit together, and to show the matching saw cuts on each.
Printing models of bones is only the beginning for 3D printing in forensic anthropology. Creating casts of footprints is another common piece of evidence used in court. Though often, first responders to a crime scene can only capture photos of footprints, so that making a cast is impossible. Now, advanced photogrammetry software and a digital camera are all they need to 3D print a footprint cast from a photo.
3D scanning can also help with the identification of human remains. The Central Identification Laboratory of the Joint POW/MIA Accounting Command is doing just that by scanning and printing 3D models of remains and superimposing the model with photographs of different faces to create a match. Their goal is to accurately identify remains of American soldiers found after military conflicts.
Traditionally, documenting fingerprints found at a crime scene is done by collecting them using powder and tape, and then creating a high resolution image. Scanning and printing blown up models of these fingerprints is another new application of 3D technology. It makes it easier for examiners to ensure an accurate match, as all finger prints have highly detailed surfaces with unique curves, ridges, and pores, which become more visible with larger models. This not only allows investigators to make comparisons, but also helps prosecutors demonstrate similarities to a judge and jury.