R.W. Snook & Co. Reconstruction Services

A Safer, More Accurate Way to Reconstruct Collision Sites


Bob Snook has worked with CSDS for nearly three decades – first as a sergeant with the California Highway Patrol (CHP), and now as an independent consultant specializing in accident investigation and reconstruction services.

“When I was with CHP, whenever we needed help with our equipment, the CSDS crew would bend over backwards to help us. They weren’t just trying to sell me the most expensive, top-of-the-line equipment. They were trying to figure out exactly what would fit my needs.”

In 2009, the 30-year officer left the Highway Patrol and opened R. W. Snook & Co. Reconstruction Services in Galt, California. As a certified Accident Reconstructionist, Snook has served as an expert witness in civil and criminal cases throughout California. His client list includes PG&E, Union Pacific, numerous district attorneys, and private law firms.

Unlike his days with CHP, when he was the first to respond to an accident, now Snook may be called into a case years after the collision occurred. His job is to gather all the data available, and compare that to what law enforcement officials originally collected.

“In a 5-year-old case, the cars may have been scrapped and the skid marks on the road have long faded away,” Snook says. “But the basic reconstruction process is the same.”


For the best combination of accuracy and safety, CSDS recommended an upgrade from Snook’s old Nikon total station to a Trimble robotic total station.

Before total station technology, Snook says an officer could manually collect maybe 30 data points in an hour, within an inch or two accuracy. Now, he can collect hundreds of data points with a total station, down to a centimeter accuracy. Plus, with the robotic total station, Snook can complete a survey by himself, with no need for extra manpower.

“If you asked me what the biggest feature is, I’d tell you it’s safety,” says Snook, who no longer has to bend over to read a tape measure or turn his back to traffic. “But if you look at it from the court’s standpoint, it’s accuracy.”

He explains that the reconstruction of any collision is based on physics and the laws of motion. “That hasn’t changed,” Snook adds. “What has changed is the ability to collect better and more accurate data. To that end, the total station has been a huge upgrade across the industry because it allows for more accurate data plotting and more data collected.”

The Future: 3D Scanning?

The veteran officer sees technology playing an increasing role in accident investigation.

First, the cars themselves are becoming more sophisticated and more electronic, with event data recorders – often called “black boxes” – now found on most vehicles.

“The more technology we put in our cars, the more data they report,” Snook says. “In the future, instead of going out and measuring skid marks, we’ll just plug into the car and get the data.”

Second, the technology to investigate and reconstruct a collision scene is already taking a huge leap forward with 3D scanning.

“We went from the roller tape, where we were getting tens of points, to the total station, where we were getting hundreds of points, to 3D scanning, and that lets us collect millions of points,” Snook says.

With the data points he collects with a total station, Snook produces a forensic map, scale diagram or simulation of the crash site. But with the added data available through 3D scanning, he can use animation software to re-create the collision event in video format.

Although Snook has outsourced 3D scanning in the past, he is considering another investment in this latest technology. It’s another opportunity to work with CSDS and the head of its Forensics unit, Jack Taylor – someone Snook knew “when we were both cops.”

For Snook, it’s all about the relationship.

“CSDS is willing to work with you,” he says. “They’re willing to spend the time to get you the product, the training and support you need. That makes a huge difference to me.”

How can a total station or 3D scanner enhance your forensics investigations? Contact Jack Taylor at solutions@csdsinc.com to learn more.