Difficult evidence will always require forensic expertise. The process surrounding it does not have to be equally difficult. Better methods can give challenging samples another opportunity to provide information, accessible collection tools can help clients use those methods more readily, and better laboratory systems can protect analysts’ time for the decisions that require their judgment.
Several years ago, officers responded to a fatal shooting. Very little physical evidence was recovered from the scene: one fired cartridge casing and one live round.
At many forensic laboratories, these items might not have been processed for DNA. Fired casings have historically produced limited results, and laboratories balancing large caseloads against limited resources must make difficult decisions about which evidence to prioritize. In this investigation, however, the casing represented one of the few remaining opportunities to identify the shooter.
DNA Labs International processed the evidence using SPENTSHELL®, an approach developed specifically for fired cartridge casings and live ammunition. DNA recovered from the evidence ultimately contributed to the identification of the individual responsible.
The case showed what can happen when a method is designed around the evidence rather than adapted from a more general workflow. It also helped demonstrate that improving results begins well before analysis.
Starting with the Right Questions
SPENTSHELL is a specialized collection and processing strategy intended to improve DNA recovery from fired casings. Using it effectively begins with understanding the evidence.
How many casings were recovered? How many shooters may have been involved? Is blood visible on any of the items? Were the casings already processed for firearms or fingerprint evidence? If so, how were they handled?
The answers help determine which items should be processed and how the resulting profiles should be evaluated. Rather than treating every casing alike, analysts can develop a testing strategy based on the circumstances of the case and the history of the evidence.
DLI SPENTSHELL Collect™ extends access to this type of collection beyond DLI. The tool can be used by any trained client representative, giving agencies and laboratories more flexibility in how they approach fired cartridge casings. Clients can apply a collection method developed for this evidence type without depending on one specialist to be available whenever a casing needs to be handled.
The result is a more accessible and consistent approach to evidence that may previously have been considered unlikely to succeed.
Different Evidence, Different Problems
Skeletal remains require another specialized approach. Environmental exposure can degrade DNA, and contaminants from the surrounding conditions may interfere with extraction. Previous testing may also have consumed part of an already limited sample.
DLI developed proprietary bone-processing protocols to maximize DNA recovery under those conditions. These protocols have produced usable profiles from remains that failed to yield results through previous testing. They do not make skeletal evidence predictable, but they give analysts another way to approach samples for which a conventional method may offer little information.
Both SPENTSHELL and DLI’s bone processing begin with the same decision: identify what makes the evidence difficult, then choose a method developed around that problem. The benefit is not novelty for its own sake. It is the possibility of recovering information that can help an investigation or identification continue.
Making the Routine Work More Routine
Analysts also encounter difficulty that has little to do with the condition of the evidence. Completing a case may require moving among multiple programs, spreadsheets, notes, and manual checks. Time spent transferring or locating information is time that cannot be spent reviewing evidence, interpreting data, or developing a testing strategy.
Helix LIMS™ was designed by working DNA analysts to bring those functions together. The configurable system supports case and worksheet management, experiment planning, contamination checks, inventory, instrument records, DNA profile management, and other parts of the forensic workflow. Because laboratories can configure it around their own procedures, they are not required to force an established workflow into a rigid system.
Helix reduces the number of places analysts must look and the amount of information they must handle manually. The scientific decisions remain with the analyst, where they belong.
Another Path Forward
No technology can make every item of evidence produce a usable DNA profile. Fired casings and skeletal remains will continue to challenge forensic scientists, and the results will still require careful interpretation.
What can change is the amount of unnecessary difficulty surrounding that work. A method designed for the evidence can improve the opportunity for recovery. A collection tool placed in clients’ hands can make that method easier to access. A laboratory system designed around analysts can reduce the repetitive work competing for their attention.
As the fired casing in this investigation demonstrated, difficult evidence may still offer another path forward.