Expertly Speaking

Lug Nut Expert Witness

Lug Nut Damage Analysis

Robert T. Lynch, P.E., Principal Collision Reconstruction Engineer

Often in lane change collisions involving commercial vehicles on a highway, the exposed lug nuts from a steer tire on the commercial vehicle will create obvious damage to the door(s) of a passenger vehicle, with little to no damage to the truck itself. The lug nuts will dig into the side of the vehicle and create a circular swirl pattern from the rotating wheel which is imprinted onto the doors and/or panels while the vehicles are in contact with each other.

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Expert Witness Podcast

Call Your Next Witness: Episode 12 – Justin Schorr of DJS Associates

Justin P. Schorr, Ph.D., Principal Collision Reconstruction Engineer

Call Your Next Witness, a podcast about civil defense and insurance coverage strategy hosted by Brian Gibbons and Georgia Coats, featured Justin Schorr, Ph.D., Principal Collision Reconstruction Engineer and President of DJS Associates for the August 4th episode. Their discussion included potential challenges of Autonomous Vehicles, the use of Biomechanical v. Collision Reconstruction engineers, and the importance of experts “staying in their own lane.”

Listen to the full podcast here:

Justin P. Schorr, Ph.D., Principal Collision Reconstruction Engineer with DJS Associates, Inc., can be reached via email at or via phone at 215-659-2010.

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Chevy Bolt Catching Fire

Chevy Bolts Catching Fire, What’s Really Going On?

Yuri A. Apel, Senior Electrical / Automotive Engineer

Over the past two years there have been more than 10 reported cases of 2017-2019 model year Chevy Bolt electric vehicles catching fire.  While not much information has been released by GM and their battery supplier LG Chem, there have been multiple attempts to repair the problem. 

After several attempts of rectifying the battery issue with software updates and warning customers not to charge their vehicle indoors (in case of fire), GM has finally opened a Recall Campaign to replace the batteries in 2017-2019 model year Chevy Bolts.  

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Venmo Expert Witness

Venmo Data in Forensic Investigations

Timothy R. Primrose, Mobile Forensic Analyst

Venmo, owned by PayPal, is a mobile payment service that allows users to pay and request money from other users. Once money is received, a “Venmo Balance” is created. Money in the Venmo Balance can be utilized for future transactions through Venmo, or can be transferred to the linked bank account. 

Venmo data can be utilized in forensic investigations and can be subpoenaed, or the data can be requested directly from Venmo by the owner of the account. Below is some of the data I received from Venmo, which contains transaction history for the month of September in 2020. Venmo retains all of a user’s transactions, dating back to when Venmo was created in 2009. 

Note the different datatypes presented in the table below including timestamps of when the transaction occurred; whether a payment was made or if money was transferred to the bank; whether payment failed or was complete; description of what the transaction was for; parties involved in the transaction; amount of money transacted; where the money came from; and, where the money was transferred to. Within the notes column, there are some illegible characters. These characters represent emojis. Emojis are not viewable in this format, but if you look below the table, we can still view the emojis employed.

Venmo Transactions


Venmo data can be evaluated to discover associates of a given person of interest. Frequent transactions with someone may bring a new suspect to light. In a drug investigation, investigators may analyze Venmo transactions to trace activity back to a drug dealer. 

Case Study: After being pulled over for a routine traffic violation, police found three grams of cocaine in the defendant’s vehicle. During his deposition, the defendant stated that he gets his cocaine on Thursday nights and typically spends $500. The defendant refused to give up the name of his drug dealer. Upon review of the defendant’s Venmo account activity, weekly transactions with “Pablo Escobar” in the amount of $500 every Thursday around 7:30pm were uncovered. The note that described what the transactions were for included the snowflake emoji. “Snow” is a known slang for cocaine.  Of course, Pablo Escobar was not the name listed in the account activity, but we were able to ID the drug dealer based on the first and last name available. 

Venmo data has endless applications in the forensic world. Showing that someone paid their friend $15 for Applebee’s provides investigators with a potential witness and location of where the person of interest was prior to an incident. Venmo data may be overlooked in scenarios involving a DUI. Learning where the driver was drinking can lead to statements from the bartender or wait staff indicating how much the person drank. If you ever have a case that you need to know what events occurred prior to an incident, consider collecting data from Venmo, social media platforms, or the person’s cell phone. 

Timothy R. Primrose, Mobile Forensic Analyst with DJS Associates, Inc., can be reached via email at or via phone at 215-659-2010.

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Platform Lift

The Lack of a Latch

John R. Yannaccone, P.E., Principal Mechanical Engineer

Case Description: In a truck, two laborers were moving tools and equipment, including a platform lift, to a jobsite. When they arrived at the site, one of the men climbed into the truck and began unloading the items. As he raised the top of the platform lift, one of the legs fell from its stowed position to the open position, landing on the other man’s hand, which was located on the tailgate of the truck. The impact of the lift’s leg caused several fractures and other related injuries to the man’s hand.  

Steps Taken: An inspection of the lift was conducted to determine why the leg opened when the lift was raised. The inspection revealed that, while the legs had brackets and pins to secure them in both the up and down positions, the pins had to be manually installed by the users. Though it would be obvious to the lift user if a pin was not inserted while in use, the same would not be so obvious to someone simply transporting the lift in the stowed position. The laborers unloading the truck were not involved in loading the equipment and were first exposed to the lift during unloading. It was unclear who had placed the platform lift on the truck or used it last. 

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Water Park Expert Witness

Water Park Lawsuits

Tom J. Griffiths, Ed.D., Aquatic Safety Expert

When it comes to waterpark lawsuits, two trends become apparent: Drownings in wave pools and accidents on waterslides.

Concerning wave pools, these manufactured “ocean” environments become hazardous when weak swimmers attempt to swim in strong waves where water reaches over their heads. It’s hazardous enough for weak swimmers to swim in deep water. When you add strong waves, many swimmers simply become too fatigued from fighting the rising and falling water.

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