Getting DNA From Shell Casings

Guest article by Francine Bardole. Originally published in Evidence Technology Magazine.

Getting DNA from spent shell casings has been a difficult, if not impossible, forensic challenge for law enforcement over the years. It was believed the heat from the firearm when a round is shot destroys the DNA. Despite this widespread belief, police continue to submit their casings to be swabbed, often getting minimal results, if any. There comes the point when you begin to think, "Why do I keep doing this when I keep getting the same results?"

Consider the definition of insanity: "Insanity is doing the same thing over and over again and expecting different results." Do we continue to do this because "it's the way it's always been done," or "it doesn't cost anything?" Either way, critical evidence is lost or cross-contaminated during the traditional swabbing method, fuming, latent print processing, and entry into the National Integrated Ballistic Information Network (NIBIN).

Enter a revolutionary technique that can obtain 26% more DNA from spent shell casings than other methods. Getting 26% more DNA from shell casings makes this method incredibly important for case resolution. The author, Francine Bardole, developed this technique. It is the most recent of methods to enhance DNA recovery from problematic metal surfaces and has been labeled by some forensic scientists as "revolutionary."

“It all comes down to the DNA that is collected in the nooks and crannies invisible to the naked eye…,” [said Bardole]. “Basically, the traditional methods of getting DNA off live rounds, and especially spent shell casings, is swabbing… Very rarely do they get enough DNA to prosecute, or to find someone. It's not that it's never happened—but it's very rare."

Bardole found herself looking at shell casings several years ago, and skin cells, and logically reasoned that there had to be a forensic method to get evidence that had to be there, but hidden.

"As I'm looking at these, I'm thinking, there's so many divots and grooves in a bullet, and the skin cell isn't this nice little soft, smooth surface," she recalled. "It could probably embed itself in these little grooves and letters, and where the firing pin goes ... because they're a little jaggedy, they could embed themselves there." —Seth Augenstein, “DNA off Spent Shell Casings a Matter of Getting in the Nooks and Crannies,” Forensic Magazine, 2018

This theory was later substantiated by scientists researching the Bardole Method.

Spent casings typically have rough surfaces with many divots and grooves and microscopic crevices into which shed skin cells can embed, limiting the prospects of obtaining DNA evidence by swabbing from the surface… The Bardole method is relatively simple, expeditious, and does not cause leaching of metallic ions, which causes DNA damage, or erode ballistically vital rifling as in the soaking method. Furthermore, it increases DNA yield to the extent not possible with standard swabbing due to its ability to recover shed cells from small irregularities on the metal surface. —Dan Osei Mensah Bonsu, Denice Higgins, and Jeremy J. Austin, “Forensic touch DNA recovery from metal surfaces – a review,” Science and Justice, 2020

With the discovery of the Bardole Method, DNA is now obtainable from those little nooks and crannies that were once considered unobtainable.

Traditional swabbing methods rarely obtain enough DNA from spent shell casings to compare to a suspect. These cases are often shelved with the idea there is no more that can be done. Thanks to this method, something can be done. —"An Interview with Senior Crime Scene Investigator and Forensic Analyst Francine Bardole,” HuntAKiller.com

Before long, the Bardole Method will be a common term among all law enforcement and forensic scientists! It's a proven and simple method to collect forensic DNA off of small objects, and like many methods and inventions, it was inspired by a hard working person who was frustrated and knew there had to be a better way! —M-Vac Systems, Facebook post, 2018

Not Just Shell Casings

The Bardole Method is a method of separating and isolating DNA material from small evidence items. The application could include many items that are currently difficult to sample, like shell casings, fingernail clippings, rings, gun parts, keys, bomb fragments, and other small items.

Road Rage Shooting

In a random road-rage incident on June 6, 2016, a man was shot in the neck in West Jordan, Utah. The victim survived, and the shooter fled the scene. Investigators later caught up with the suspect, nicknamed "Cyko," in a neighboring town. Police did not have the car, but they did have the spent shell casings.

The Bardole Method was used, and weeks later, police got their results: “the full DNA profile of the shooter. It matched a swab taken from “Cyko” Granados. Found guilty at trial, he was sentenced to at least four years in prison in December 2017 in the attack.

"A swab can't get down into those nooks and crannies—it can't get down into those areas," said Bardole in an interview with Forensic Magazine in 2018. "You have got to get what's embedded."

Shooting Homicide

In one shooting homicide case, three spent shell casings were collected and proved to be the only items of evidence. The Bardole Method was used on the casings, and DNA was developed from the casings. A Major DNA Profile was obtained and uploaded into the CODIS database. This was a phenomenal result from three shell casings!

It is essential that the shell casings are not cross-contaminated with chemicals, fuming, latent print powders, or handled without sterile gloves and mask before submitting for Bardole Method DNA extraction. NIBIN entry can easily be done after processing with the Bardole Method.

The M-Vac: A Valuable New DNA Collection Tool

The developments in collecting and analyzing DNA trace evidence are very exciting. DNA has revolutionized criminal investigations and will continue as technologies and testing improve. Unfortunately, many law enforcement agencies are not aware of these technologies and developments which could help solve cases.

The M-Vac can be thought of as a miniature hand-held carpet cleaner. However, instead of spraying a cleaning solution, the sampling head sprays nuclease-free, DNA-free, sterile buffer onto the item of interest. As the buffer is sprayed, DNA present on the item's surface is released from the substrate. It is vacuumed up by the constant vacuum that is simultaneously applied by the sterile, single-use sampling head.

Once the item is sampled, the liquid containing DNA from the evidence is captured in a collection bottle, transferred to a sterile filter, and filtered through under vacuum pressure. Once dried, the filter can easily be removed and processed for DNA. Image: M-Vac Systems, Inc.

The M-Vac DNA collection system can collect trace or touch DNA from clothing, bedding, tape, rock, rope, and other porous materials often touched by the suspect, left at the scene, or on the victim. Often traditional swabbing methods cannot get into the small weave or pores of an item. (See graph below)

Many variables come into play when it comes to solving cases. The investigators, crime scene experts, witnesses, evidence, forensic experts, technology, financial resources, etc., are intricate to the solving and closing cases. It has been my experience that the best results are achieved through communication and cooperation between all involved.

Reaching out to experts in the criminal justice fields, forensic disciplines, and technologies can help bring closure to a case much sooner than individual efforts. The sooner the case is solved, the sooner the perpetrator is off the streets, and the community is safe from further victimization.

About the Author

With more than 30 years in the field of criminal justice, Francine Bardole has invested the past 20 years becoming an expert in her field of crime scene investigation and forensics, educating students and investigators, helping solve cold cases, discovering and implementing a superior tool for collecting DNA, and giving a voice to silent victims. Bardole has specialized in the field of forensic serology and DNA because she felt having a better understanding would prove to be an asset when working with law enforcement at crime scenes and determining probative evidence.

With her desire to help solve cases, Bardole opened Cold Case Solutions and Resources. She offers free consulting from the crime scene to find the most probative evidence for DNA processing and the entire laboratory processes. She utilizes the M-Vac and Bardole Method to extract touch DNA from items of evidence in both cold and new cases. Working together and understanding the best technology, laboratory, and forensic experts for a case is essential to the outcome.