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3D laser scanning revolutionizes construction site accident investigation and evidence collection

In early October 2012, several construction workers were killed or injured when the Miami Dade College parking garage collapsed like a pancake, trapping a then-unknown number of workers inside (See http://tinyurl.com/9956xae). Some survived, but some did not.

Post-accident site investigation

Since this tragic loss of life, injury, and property damage, lawyers have no doubt already begun what will be expensive and lengthy litigation. The owner, architect, engineer, contractor, subcontractors, construction workers and their families will all play a part.

The evidence may be sifted and sorted for years before any judges or juries hear about what happened on that fateful day.

Ideally, each party would have ample opportunity to investigate the site, take measurements, and form opinions as to what happened. However, this was not an option in Miami.

Workers needed to be freed. The structure’s potential for further collapse endangered all those around it. The owner had a dangerous pile of rubble where a new parking garage was supposed to stand. Certainly, nobody wanted to preserve site conditions for any length of time.

So, how can evidence of existing site conditions be preserved forever? 3D laser scanners were dispatched to the site immediately.

From onsite scan to a 3D model on your computer

Similar to traditional surveying, 3D laser scanners are set-up on tripods and use light to precisely measure their surroundings. But whereas traditional land surveying instruments take only one measurement at a time and need a reflector to return the light, 3D laser scanners take millions of measurements of everything that they can “see”  within 300 feet.

This data is collected in a matter of minutes and the instrument can be set up as many times as necessary to see the entire site. Technicians then convert this raw information into a 3D model.

Lawyers and their experts can use this model to return to the day of the accident at any time.  They can pan and zoom around the model to find any desired vantage point. Any angle or distance can be measured and re-measured.

Collecting quality evidence

After any given construction accident, investigators take photographs, make measurements and sketches, and interview witnesses.  However, even the most seasoned investigator can miss critical details due to time constraints, site access, or simple knowledge of the facts.

Once the site is cleaned up or altered in any way, the evidence is spoiled. However, 3D laser scanning allows investigators to return to the site at any time to retrieve missed or forgotten details.

Additionally, the evidentiary quality of 3D laser scanning data far outweighs traditionally collected evidence. Photographs provide only a single 2D perspective and each detail must be specifically targeted. Manual measurements are subject to observational and recording error.  Witnesses certainly cannot permanently remember every visible detail, especially in the wake of a tragedy. 3D laser scanning overcomes all of these limitations.

Full access to the site is often limited, for example, from the danger of additional collapse and loose rubble around the parking garage in Miami. This problem is also overcome with 3D laser scanning, as it uses light to measure from a distance. Anything that can be seen can be scanned and recorded for later review.

Using the model at trial

3D laser scans are not new to the courtroom and readily pass muster under evidentiary challenges. Foundation for entering a 3D laser scan on the record can be laid by a professional land surveyor, but courts nationally have allowed scans based on the testimony of laymen who were simply certified to use the equipment.

At trial, 3D laser scans provide unparalleled demonstrative exhibits. Judges and juries will no longer need to travel to visit a site.

As noted by Lt. Warren Hamlin of the Knox County Tennessee Police Department, “It’s almost like taking the jury right to the crime scene. We can show pictures all day long, but when you’ve got a panoramic view that shows exactly how it looked and where everything was, that’s a much better depiction than a photograph. … So, if a guy says, ‘I was standing in that corner,’ you could create a viewpoint exactly where his head would be and look around the model and tell whether, yes, he could see that, or, no, he’s lying.”

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David Headrick has over 14 years of experience in the surveying, engineering and legal industries, both as a project manager for LandAir Surveying and as a lawyer in private practice. He has represented numerous land surveyors, designers, architects, contractors and other industry professionals throughout his career. Today, David serves as an executive and project manager for LandAir, focused on developing and managing the company’s 3D laser scanning department. Contact him at dheadrick@lasurveying.com.

 

 

 

An armed robbery, a high speed police chase and…laser scanning?

Sometimes I don’t have to look past the front page of the local newspaper to see a good example of laser scanning in action.

Tragically, there was a police-involved shooting in Cobb County, Georgia, this past weekend, as reported by the Atlanta Journal-Constitution. The suspect allegedly robbed a gas station and then led the police on a high speed chase. The chase ended on I-75 when the suspect pointed a weapon at the police officers and was shot dead.

This was a very unfortunate incident, but the impact on the community was far lessoned due to the outstanding work of the Georgia Bureau of Investigation.

The shooting and subsequent chase left many cars wrecked and damaged and, ultimately, the interstate was forced to close temporarily. As you can imagine, this was not a calm situation.

The GBI dispatched their laser scanning team to the site to set-up and scan the area to document the evidence both known and unknown at the time. They also generated 3D photography to further document the area in its entirety.

Using this method, they not only saved time, but were also able to quickly collect the data that would be necessary if the case were to go to trial.

So why use laser scanning to document a scene like this?

First, consider the sheer size of the scene. In this case, the area of study was larger than a football field. Without scanning, investigators would have had to take multiple photographs and make measurements with total stations that shoot one point at a time or worse, measure with 100 foot-long measuring tapes.

This takes much more time, requires more people, and creates much more chance for errors. The errors could be wrong measurements or even missed objects.

When you combine the laser point cloud data with the photographic data, the measurements and the scene become much more intuitive and obvious. You can place the evidence markers by the evidence within the scene and the scanner automatically picks them up.

Instead of making and recording many different angles and distances, you simple put in the points per square foot you want to capture into the scanner and in about 15 minutes, you have a completed scan with photography.

You can look at the scan and very clearly see the markers and measure from any object in the scan to any other object in the scan. So, if you need to know how long a skid mark is, for example, you would just click two points – one at the beginning and one at the end – and the measurement would be instantly generated.

With laser scanning, time at the scene is used to locate and mark the evidence and important points in the scene. All critical measurements can be made offsite after the scene is moved and the traffic is moving again.

Here’s the most important part: If you need information about the scene, but did not know it at the time of the scan, all is not lost! If it exists in the scan, you can make all the measurements you need to document the new (previously unknown) evidence.

More and more, laser scanners are being used to document crime scenes across the country. District attorneys like the scanned data because they can easily view it.

Scanned data is totally objective in that it collects the whole scene. It is easy to put a point down on the ground every square inch so that the coverage of the site is complete. Additionally, the fact that no one has to decide what measurements are made in the field before they release traffic is very important.

Judges like the data because the jury does not have to visit the site to understand the scene. Instead, they can simply view it in 3D on a computer screen without leaving the courtroom.

Laser scanning also saves time and money. Traffic still has to be stopped for an investigation, but if not for laser scanners, it would be stopped longer and there would be less information collected.

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Tate Jones has over 40 years of experience in land and aerial surveying and was one of the country’s earliest adopters of 3D laser scanning technology. A nationally recognized expert in the field of 3D data capture, he has worked with hundreds of clients in the forensic engineering, law enforcement, criminal defense, architectural and construction industries. Contact him at tjones@3DForensicScans.com, a division of the LandAir Surveying company.

3D forensic scan helps Feds catch vandals of ancient American Indian temple

The Nez Perce Indians of Idaho lived in the Pacific Northwest for many centuries before they bumped into Lewis and Clark in 1805. A peaceful tribe who lived mostly on the natural foods available in Idaho’s rivers, they probably never imagined they would one day use high definition scanning technology.

Fast-forward to February 2010.

In a small, little known rock shelter at a national park in Idaho, vandals used spray paint to deface ancient Nez Perce tribal pictographs, estimated to be some 2,500 years old. In addition to having both cultural and spiritual significance to the Nez Perce tribe, the rock shelter is located in a national park on federal land, which makes it a very serious crime.

Our firm, LandAir Surveying, worked with the Archaeological Damage Investigation and Assessment (ADIA), the U.S. Army Corp of Engineers, and the FBI to assist in a federal investigation to prosecute the vandals and document the destruction.

This wasn’t your everyday survey.

Our crews packed up their gear and boarded a plane to Idaho. Then they rented a car and drove to an access point on the Snake River in Hells River Canyon, where a jet boat was waiting to take them to the crime scene. The ride down river was exciting and rigorous, and the drop-off point was a small piece of land in the middle of the wilderness.

The colors and materials used to create the ancient drawings made it very difficult to capture all of the detail in the pictographs. After multiple scans – using a combination of laser scanners and GPS – over two trips, our crew was able to collect enough data to create detailed images of the rock face, as well as the defaced pictographs themselves.

Once processed, the data was presented to the Nez Perce elders, many of whom were very angry as they were seeing the vandalism for the first time. When we returned, we created color drawings, digital files and spherical photography that was used to evaluate and document the damage.

But ultimately, just two years later, justice was theirs.

Two Idaho men were eventually arrested and prosecuted for willful injury or depredation of U.S. property and were sentenced this February to federal prison and fines of more than $33,000 each for defacing the pictographs. A third man is set for sentencing in June.

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Tate Jones has over 40 years of experience in land and aerial surveying and was one of the country’s earliest adopters of 3D laser scanning technology. A nationally recognized expert in the field of 3D data capture, he has worked with hundreds of clients in the forensic engineering, law enforcement, criminal defense, architectural and construction industries. Contact him at tjones@3DForensicScans.com, a division of the LandAir Surveying company.