Automated Forensic DNA Technology
Written by James Careless   

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Automated Forensic DNA Analysis Technology:
Can it clear the backlog?

AS THE APPLICATION of DNA sampling increases in law enforcement, the demands on crime labs grow—and the backlogs


increase. According to the June 2010 National Institute of Justice (NIJ) Special Report, “Making Sense of DNA Backlogs—Myths vs. Reality”, written by the NIJ’s Mark Nelson, “The demand for DNA testing is rising primarily because of increased awareness of the potential for DNA evidence to help solve cases. The demand is coming from two primary sources: (1) the increased amount of DNA evidence that is collected in criminal cases and (2) the expanded effort to collect DNA samples from convicted felons and arrested persons.”
“With the advent of CODIS, and advances in DNA testing that support much smaller samples, it is not surprising that law enforcement agencies are using DNA testing more,” said Michael Sheppo, director of the NIJ’s Investigative and Forensic Sciences Division. “Today, we can extract usable DNA samples from the skin cells left by someone who just touched a surface. A few years ago, this wasn’t even possible.”
For the forensics managers who are assigned these samples, the fundamental problem is one of capacity: There is not enough processing power within their labs to keep up with their ever-growing caseload, let alone to enable them to catch up with what is already waiting to be processed. Or, as Nelson succinctly wrote in his NIJ Report, “Myth: Backlogs are a onetime event. As long as one chips away at the backlog of untested cases, it will eventually go away. Reality: Backlogs are not a one-time event. They are dynamic and subject to the law of supply and demand. They may go down, but they may go up.”
And right now, they are going up.
The good news: Technology has advanced to the point where many of the more time-consuming and repetitive DNA processing tasks can be handled by automated robotic forensics systems. These are systems that combine software to sample, analyze, classify, and store data, as well as robotics that pipette samples, stage simple chemical tests, and move samples from one processing station to another.
“Automated robotic forensics technology can certainly help mitigate the thousands of DNA sampling cases backlogged nationwide,” said Rick Luedke, the marketing manager with Hamilton Robotics. “This is why forensics technology is filtering down from the three-letter agencies in Washington, D.C. to state, regional, and even local law-enforcement labs.”
A Real Time Saver
“The human time saved by DNA extraction robots is significant,” said Dr. Tim McMahon, senior manager of Validation Services with Life Technologies, which owns Applied Biosystems. “But it’s not just a matter of handling time: Automated and robotic systems offer more consistency in approach, better repeatability of results, and less room for error.”
“Robotic systems that handle repetitive tasks such as pipetting can really speed things up in the lab,” said Sheppo with the NIJ. “Not only can they do this work faster and more consistently than humans, but they also free up technicians to do the harder work, such as dealing with ‘dirty’ samples from crime scenes where you have to distinguish between different sources of DNA and chemical contaminants.”
What robotic systems work best in the forensics setting? Generally, the answer depends on the precise tasks that need to be done—factors that can vary from lab to lab.
Dr. Meredith Turnbough’s job is to answer this question in detail. She is laboratory manager at the Institute of Investigative Genetics’ Research and Development Laboratory, a facility that is operated by the University of North Texas Health Science Center in Fort Worth, Texas.
“A big part of my job is to help identify and develop new techniques for systemizing and streamlining casework, including DNA sample analysis,” Turnbrough said. “This is why we have been comparing three automated DNA extraction robotic systems, all of which use a magnetic bead to bind the DNA and then wash off inhibitory compounds so that we can purify it for testing.” The machines currently being tested are the Promega Maxwell 16, the QIAGEN BioRobot EZ1 Advanced XL, and the Applied Biosystems AutoMate Express Forensic DNA Extraction System.
In evaluating and comparing these three systems—all of which can process multiple samples at one time—Turnbough is trying to “keep in mind not what is snazziest, but rather what exactly meets the needs of our analysts,” she said. “This is why we have spoken with them to find out what kinds of DNA samples they need to process, what kinds of jobs are eating up manpower that could be automated, and just how much processing capacity we need and don’t need to help the situation.”
One Size Does Not Fit All
Despite using a standardized testing procedure, Turnbough and her team have found it challenging to compare the three DNA systems noted above. “The reason is that each of the robotic extraction systems do different things well,” she said. “For example: the AutoMate is easy to operate as far as the protocols go, but it only elutes the sample in 50 ml of TE solution. The EZ1 can elute using TE or water, and you can select between 40, 50, 100, or 200 ml. Meanwhile, while the AutoMate and EZ1 both use robotically-controlled pipettes to draw and move the samples, the Maxwell 16 relies on a magnetic rod/plunger assembly to transfer magnetic beads through the sequence of reagents in the cartridge.”
These are just some of the differences, she concluded. This helps illustrate how difficult it is for a laboratory to compare and decide between the various models available on the market.
The Current State of the Art
The current state of the art is based upon a collection of processing systems that handle discreet aspects of the DNA sampling procedure. It is up to either humans or robots to move the samples from one processing stage to another, and up to the humans themselves to analyze the final results and make decisions.
“Today’s technologically-equipped crime labs have a series of modular stations in place that take the evidence and turn it into an analyzed piece of information,” said Lisa Schade, head of Market Development for Life Technologies’ Human Identification Business. “The advantage of this approach is that labs can decide which stages they want to and/or can afford to automate, and which stages they will continue to do by hand.”
Even the most sophisticated automated robotic forensics systems can only do so much. “Even the best of systems are not perfect, although they can be very close,” said Omo Clement, marketing manager at Biomatrica. “Still, when compared to manual processing, automated and robotic systems offer a much higher degree of confidence.”
From a scientific analysis point of view, forensics technology is only as capable as it is designed to be, and only as good as the ideas that govern its creation. This means that a DNA extractor is just that: a DNA extractor. It is not a thinking machine that can extrapolate deductions about the evidence it is dealing with. It can merely test for what it is designed to test for—and that’s it.
This is a fundamental limit to forensics technology, but it is by no means the only one affecting today’s technology. “Sample size is another issue,” said Luedke with Hamilton Robotics. “There is a trend in forensics to work with smaller and smaller samples, in order to preserve as much of the evidence as possible. This is understandable, but the smaller the sample, the harder it is for automation to deliver a high degree of precision in its analysis. When it comes to automated forensics analysis, more is not less.”
Mixing and matching different vendors’ products is also a challenge. “It is still difficult to get a mix of systems talking to each other, so that we can be sure the robots are doing what they are supposed to be doing,” said Craig Nolde, validation services manager with Sorenson Forensics. “This is why a lot of time is being spent on interfaces and software fixes.”
Expectations are another problem. “People think that DNA typing can be used in all cases, but the truth is that you need to have usable DNA for sampling to succeed,” Turnbough said. “Meanwhile, the application of DNA testing to more and more types of crimes keeps the volume of work going up, perhaps even past what an automated lab can handle.”
Finally, there’s money: As funding is cut by cash-strapped governments, crime laboratories are restricted in their ability to deploy time-saving technology. “The public wants crimes to be solved quickly and for backlogs not to exist, but they are not willing to pay the taxes necessary to make this happen,” said Clement. “There is so much more that forensics experts could be doing to employ technology to solve cases, but they just don’t have the money to buy what they need.”
An End to the Backlog?
Since 2004, the NIJ’s DNA Backlog Reduction program has given out $330 million in grants to cover the cost of automated and robotic forensic technology projects. “The program’s short-term goal is to reduce the backlog of untested cases by providing crime laboratories with funds to work more cases,” wrote Nelson in the NIJ report. “The long-term goal is to build the capacity of crime laboratories by providing funds to purchase high-throughput instruments capable of processing multiple samples at the same time, automated robotic systems and laboratory information management systems to manage the data generated more efficiently.”
To date, Nelson said, NIJ grants have “helped crime laboratories nationwide to reduce backlogs by 135,753 cases.” The downside: “In a 2007 survey of publicly funded crime laboratories, 90 percent reported that they would not have sufficient funding if NIJ grants were no longer available,” he wrote. “They estimated that about 26 percent of their casework budget comes from NIJ. With respect to particular aspects of DNA analysis, the labs estimated that federal funding covered 10 percent of the budget for reagents, 85 percent for instrumentation and 20 percent for training.”
Clearly, say the experts, more money is needed—not just grants, but ongoing regular funding—if automated robotic forensics technology is to save the nation’s crime labs from their own success. For now, wrote Nelson, police investigators need to use care when submitting samples to the laboratory for analysis. “Submitting untested evidence in law enforcement custody for analysis could have a serious impact on DNA backlogs in crime laboratories if the evidence were suddenly submitted to a crime laboratory all at once,” wrote Nelson. “A better approach would be for investigating officers to carefully review the untested evidence and the case files to determine if forensic analysis is needed and if the laboratory would need additional elimination samples to identify suspects. Evidence may not need to be submitted, for example, in cases that have been adjudicated (either by trial or plea bargain) and in those cases where the victim has withdrawn the criminal complaint or the prosecutor has refused to file charges.”
“We are making real progress in helping forensics labs get on top of their workloads,” said Sheppo. “This is no small feat. The DNA workload at these labs has doubled in the past several years. And consider the flip side: If NIJ had not provided this grant money, our labs would be backlogged beyond belief.”
For More Information
To read the full NIJ report, “Making Sense of DNA Backlogs—Myth vs. Reality”, go here:
About the Author
James Careless is an experienced freelance writer with credits with a number of law-enforcement and public-safety publications.

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