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Hendon Publishing

New Genome Technology

Traditionally, when DNA samples collected from a crime scene did not match either the DNA of a potential suspect or samples from various law enforcement databases, it would mean a setback for the investigation and potentially a dead end for the DNA evidence.

With recent advancements in next-generation sequencing, however, the investigation does not need to end there. One of the most important scientific breakthroughs in forensics in the last 20 years could lead to a way to unlock biological clues and indicators within complex DNA samples that were previously hidden.

The Human Genome Project, which was completed in 2003, identified thousands of biomarkers applicable to DNA-based forensics. With this important discovery, the National Institute of Justice saw an immediate opportunity for applications within law enforcement. Currently, forensic analysts can use some simple analysis to match a known suspect’s DNA to the biological samples found at the scene of a crime, but extrapolating that same sample to the larger population is much more challenging.

To further develop this technology for law enforcement, the NIJ issued a grant to the Battelle Memorial Institute, the world’s largest independent research nonprofit. In 2014 Battelle developed ExactID™, the first commercially available software tool designed specifically for the analysis of next-generation sequencing (NGS) data. With the help of this grant, Battelle will be able to further develop tools that use NGS to unpack the complex clues found within DNA evidence.

NGS technology takes DNA analysis one step further, allowing law enforcement to draw important conclusions from the analysis of a single “unmatched” DNA sample. The new DNA sequencing and bioinformatics technologies are transforming DNA into an informative and scientifically reliable crime-scene witness. With this technology, law enforcement will soon be able to evaluate a series of biomarkers found in the evidence and predict important physical and ancestral characteristics to support an investigation.

What exactly does this research mean for law enforcement? Take this example: Detectives are investigating a crime scene where they haven’t yet identified a suspect. The investigators, however, were able to identify a small DNA sample, maybe from a stray piece of hair, a discarded cigarette, or an empty beer can. They cross test this sample against their database, the FBI’s database, and their list of suspects, but their search doesn’t turn up any positive results. Previously, this would mean the DNA marks a dead end for the search for a suspect.

Up to this point, forensic DNA analysis methods have centered on matching DNA profiles from a crime scene against DNA profiles of convicted offenders previously entered into law enforcement databases such as the FBI’s CODIS database or the UK’s NDAD database. The idea would be to find out if the perpetrator of the crime is already known to police from previous crimes. Under that paradigm, if the crime scene DNA profile does not match any DNA profile already in the database, then little else can be learned from the DNA that helps the investigation.

But now, using this new technology, DNA can help identify suspects by revealing information about the physical appearance and ancestral heritage of the DNA source recovered from the evidence. Some clues are similar to what an eyewitness can provide, but in many ways DNA evidence is more objective and reliable, and often more credible in court. 

This is possible due to the massive increase in biomarker sequencing throughput, which creates both a tremendous opportunity and a potential problem. The new sequencing technology has yielded the ability to research previously unknown aspects of the human genome, but also has had the unintended consequence of ballooning the complexity and cost of analyzing sequence data. The time and cost limitations in DNA analysis quickly switched from the sequencing process itself to bioinformatics analysis of the sequences.

Traditional bioinformatics algorithms were poorly equipped to handle key features of NGS data: very large data sets, non-trivial error rates, and extensive fragmentation of the sequenced DNA into short segments that are reported in no particular order. Enormous numbers of randomly ordered short reads containing errors make for a challenging bioinformatics situation akin to assembling a very large jigsaw puzzle where some of the pieces are wrong.

The solution has come in the form of computationally efficient algorithms that are robust to the new data features. An avalanche of new algorithms has become available, with more being published every month. Tomorrow’s technology will rely upon a class of algorithms that eschew the traditional sequence-analysis strategies and instead approach the analysis of DNA sequences as a signal-processing problem. The benefits are vast increases in speed along with higher stringency of results, and a less mysterious and more approachable bioinformatics process for forensic DNA analysts to use. 

Due to the technology’s affordability and ease of use, ExactID has already sparked the interest of a number of local law enforcement agencies. After a showcase at the International Symposium of Human Identification (ISHI) conference in the fall of 2014, law enforcement officials and forensic analysts from across the country immediately drew connections to how this technology can benefit their work.

Expanding the power of DNA testing is crucial to the future of law enforcement and crime scene investigations, and the National Institute of Justice has taken notice. The grant was part of a strategic roadmap that will explore and increase the capabilities of DNA found at crime scenes.  

As we learn more about next-generation sequencing, it’s important that our country’s law enforcement agencies are able to utilize this revolutionary technology to better catch criminals and eliminate threats to public safety. Thanks to the NIJ’s forward-thinking grant, the DNA information unlocked from next-generation sequencing has the real ability to benefit law enforcement—even at the local level. With ExactID, local agencies can now analyze forensic data and identify suspects faster, more accurately, and more cost-effectively—in turn, improving public safety for all.

 

Rich Guerrieri, Research Leader for Battelle’s Applied Genomics business unit. Guerrieri has more than 30 years of forensic laboratory experience, including nearly 20 years with the Federal Bureau of Investigation (FBI) and the Army Criminal Investigative Laboratory.





Published in Law and Order, Jan 2016

Rating : Not Yet Rated


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