Using LIDAR to find unmarked graves of murder victims

August 2, 2018 by Bob Yirka, Phys.org report
Credit: CC0 Public Domain

A team of researchers affiliated with several institutions in the U.S. reports that LIDAR can be used to find the unmarked graves of murder victims. In their paper published in the journal Forensic Science International, the group describes the technique and how well it worked.

Oftentimes, a murderer will seek to hide the body to avoid being caught and imprisoned. One well-known method of victim hiding is simply to bury the body in a remote location. This approach has proven effective in the long run, as nature will eventually hide evidence of digging—but not all of the evidence, it seems. The researchers in this new effort noted that when a body is buried, it takes up a certain amount of room beneath the ground. But as the body decays, it takes up less room, causing the dirt above to settle. This slight bit of settling can look like a depression on the surface of the ground to the observant eye—though less so when covered by debris such as scattered leaves.

The researchers noted that LIDAR has proven to be quite effective at mapping terrain—one example was its use in uncovering hidden Mayan ruins in the Amazon. LIDAR is an acronym of the words "" and "radar." It is used in the same way as radar—light beams, in the form of laser blasts, are fired at the ground, and a sensor reads how much light is bounced back. Improvements over time have led to LIDAR systems that can detect changes in ground texture to the centimeter.

Because of its accuracy, the researchers wondered whether LIDAR could be used to find unmarked graves. They obtained several corpses that had been donated to science and buried them in several unmarked graves. Some of the graves held just one , others held more, and of course, one held none to serve as a control. The researchers then flew over the graves in a helicopter periodically for almost two years and monitored the ground using LIDAR. They report that they were able to make out the outlines of all of the graves—even those that were covered by leaves and other debris.

Explore further: Searching for clandestine graves with geophysical tools

More information: K.A. Corcoran et al. A novel application of terrestrial LIDAR to characterize elevation change at human grave surfaces in support of narrowing down possible unmarked grave locations, Forensic Science International (2018). DOI: 10.1016/j.forsciint.2018.05.038

Abstract
Unmarked graves are difficult to locate once the ground surface no longer shows visible evidence of disturbance, posing significant challenges to missing person investigations. This research evaluates the use of terrestrial LIDAR point data for measuring localized elevation change at human grave surfaces. Three differently sized human graves, one control-pit, and surrounding undisturbed ground, were scanned four times between February 2013 and November 2014 using a tripod-mounted terrestrial laser scanner. All the disturbed surfaces exhibited measurable and localized elevation change, allowing for separation of disturbed and undisturbed ground. This study is the first to quantify elevation changes to human graves over time and demonstrates that terrestrial LIDAR may contribute to multi-modal data collection approach to improve unmarked grave detection.

Related Stories

Searching for clandestine graves with geophysical tools

May 13, 2013

It's very hard to convict a murderer if the victim's body can't be found. And the best way to hide a body is to bury it. Developing new tools to find those clandestine graves is the goal of a small community of researchers ...

Seeing the forest through the trees with a new LiDAR system

June 27, 2017

Shortly after lasers were first developed in the 1960s, LiDAR—whose name originated as a combination of "light" and "radar"—capitalized on the newly unique precision they offered for measuring both time and distance. ...

Spain: Search resumes for poet Lorca's burial place

September 19, 2016

Archaeologists are back searching for an unmarked grave in southern Spain where the acclaimed poet Federico Garcia Lorca is believed to have been buried following his execution at the start of the Spanish Civil War.

Volvo likes what its self-driving weavers see in Luminar

June 17, 2018

Self-driving car news for June would not be complete without mention of Volvo. Luminar has rolled out a beefy development platform and has struck a relationship with Volvo—being that the Swedish carmaker chose Luminar to ...

Recommended for you

Ancient mice discovered by climate cavers

September 24, 2018

The fossils of two extinct mice species have been discovered in caves in tropical Queensland by University of Queensland scientists tracking environment changes.

The first predators and their self-repairing teeth

September 24, 2018

The earliest predators appeared on Earth 480 million years ago—and they even had teeth capable of repairing themselves. A team of palaeontologists led by Bryan Shirley and Madleen Grohganz from the Chair for Palaeoenviromental ...

Fat from 558 million years ago reveals earliest known animal

September 20, 2018

Scientists from The Australian National University (ANU) and overseas have discovered molecules of fat in an ancient fossil to reveal the earliest confirmed animal in the geological record that lived on Earth 558 million ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

gwrede
1 / 5 (1) Aug 02, 2018
Well. Time to always have a few planks in the car.

Now all one needs is to dig a foot deeper, bury the vic as before, then lay out the planks and the last foot of dirt. Oh, and don't forget to use pressure impregnated planks.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.