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What constitutes a good forensics LIMS? Proper selection requires careful review of needs and processes.

While it is common for users in various laboratories and industries to feel that their processes are unique, in many ways, they all have common needs. Similarly, in many respects, all laboratory information management systems (LIMS) are alike, or at least they should be. All must perform basic functions, such as track the users entering data, track the samples arriving at the laboratory and their processing through it, and generate analysis reports, while maintaining data integrity, throughout the whole process.

Admittedly, some systems do not do this as well as others, but that's a separate issue. However, those shrilly promoting their uniqueness are correct in some ways, as there are definitely differences in the terminology used in different types of labs and how samples are handled. Most good commercial systems are flexible enough to deal with this variation, though some might have difficulty with the difference in emphasis that certain industries assign to various functions. This issue becomes a major problem when a single entity becomes a microcosm reflection of this disparity.

In practice, the more diverse the san> pies that the laboratory must handle, the more likely they are to encounter this issue, as different sample types sometimes require radically different sample processing steps. Of all the disciplines that might employ a LIMS, the forensic laboratory is one that potentially has the most diverse needs. I say potentially, as not all forensic laboratories are the same in terms of the variety of samples they handle. In some jurisdictions, analysis of a particular type might be farmed out to another laboratory, whether because the local lab didn't have the sample volume to keep the necessary experts on staff or for some political reason. However, as one reason for installing a LIMS in a forensic laboratory, is to assist with case management, using this outsourcing to justify purchasing a less capable system can be rather short-sighted, as at some point the test results for the outsourced samples will be coming back into the system, so you need to make sure you have a place to store them.

Perhaps the best way to appreciate this is to realize that, in pragmatic terms, there really isn't such a thing as a forensic laboratory, at least not in the same way that we might refer to a water analysis laboratory or a drinking water treatment plant, just to pick an example. Instead, it is more accurate to think of a given 'forensic laboratory' as an umbrella organization that shelters a variety of much more specialized laboratories. In the article "Crime Lab Design" (1) the authors view a forensics laboratory, as a 6-in-1 structure, segmenting the organization into six specialized laboratories:

* Biology: Designated for the analysis of DNA and other biological samples. This module is designed and equipped as a full-spectrum biological laboratory, including isolation systems to avoid contaminating DNA evidence and to minimize personnel exposure to any potentially infectious agents.

* Chemistry: Designated for the chemical analysis of samples by wet chemistry and instrumental methods, including the analysis of narcotics and related materials. This module includes fume hoods and other equipment for the safe preparation and analysis of samples.

* Toxicology: Designated for the examination of body fluids and tissues for drugs, as well as the identification and quantitation of foreign substances. It requires a combination of the biology section and chemistry section building features.

* Latent fingerprint: Designated for the recovery and analysis of latent finger prints from evidence.

* Firearms: Designated for ballistic and related firearms analysis. This frequently requires some type of sound-isolated firing range, as well as wet chemistry support. May well also house a firearms comparison collection.

* Trace evidence: Designated primarily for chemistry trace analysis below the levels normally handled by the chemistry section using both optical and electron microscopes.

However; it would not be uncommon to find other designated sections, with their own special requirements, as well. Additional specialized sections commonly encountered include arson analysis, questioned documents, a forensic garage for vehicle analysis, et al. Some may further segment the above list into additional self-contained sections. According to the "Crime Lab Design" authors, each laboratory section must consist of an isolated securable module to meet accreditation requirements.

Each of these fields tends to have its own terminology and processing workflow. It is possible to obtain specialized systems in all of those fields (or customize a general purpose LIMS to match the labs work-flow), and this optimization might make sense for large operations or commercial laboratories that perform only the one type of analysis. However, for most multi-disciplinary forensic laboratories, the value of the LIMS is greatly enhanced by using it to tie together the test results from all of the different laboratory sections that affect a given case. This integration of case information means that the LIMS also can be used to manage staff workflows in the various lab sections (2) and provides a central nexus for reviewing the status of testing regarding a case. It also provides a better big-picture look at what all of the evidence means.

In addition to being able to handle the diverse sample types arriving in the laboratory, such as DNA and ballistics evidence, another factor that must be considered when selecting a forensic LIMS is the difference in emphasis that a forensic lab places on the various features of a LIMS compared to other types of laboratories, as well as variations within its own staff. By the very nature of the system, one of the biggest emphases is going to be on chain-of-custody, for anything with a broken chain-of-custody is likely to be thrown out when submitted at a trial. This is one reason to make sure that the selected system supports the generation of barcodes, preferably both I-D and 2-D types.

Almost a corollary to the chain-of-custody is that the systems have a very aggressive audit trail that tracks ANY changes made to the system data. Within the lab, an Ames Laboratory study from 2005 (3) shows that feature priority is placed on:

* chain-of-custody by evidence technicians

* report generation and tracking of daughter evidence by scientists

* chain-of-custody and management reports by lab managers

* the overall relative order of these items tends to vary with laboratory size


The actual report breaks this down into much more detail, the point being not to let any single feature be the overriding criteria used to select LIMS for use in a forensic laboratory.

Even though somewhat dated, the Ames report makes fascinating reading, and it would be prudent for anyone considering acquiring a LIMS for a forensic laboratory to review it, as the prioritization of the desired features and other selection criteria has not changed significantly. It is also useful as a tickler for other items to consider; particularly if you haven't tried to select a LIMS before, as it is very easy to lose sight of all the factors that should be considered and focus on those items you know. While it does not cover them in depth, it also takes a look at other regulatory standards that either the LIMS must meet or how the LIMS can assist the overall lab in meeting them.

To maximize the benefits of installing a LIMS, the laboratory also should maximize its automated instrumentation. This normally doesn't result in reduced staffing, but instead means that existing staff can focus more on performing their analysis, as opposed to performing evidentiary bookkeeping. A brief introduction, with some very pragmatic recommendations, can be found in an article by Cristopher Cowan and Melissa Schwandt. (4) Admittedly, this article comes with something of a DNA laboratory orientation, but its basic recommendations should be applicable to any laboratory section.

The primary justification for automation in any laboratory, and I would particularly emphasize the instrument/ LIMS interfacing aspect of laboratory. automation, is the resulting reduction in the number of transcription errors. Even more than in other types of laboratories, the accurate transfer of information through the system is critical, as any one error could potentially result in an entire case being thrown out. This is another reason that support for barcodes and/or radio frequency ID (RFID) tags in the LIMS is so important, although both have their own sets of issues and aren't magic bullets.


A corollary to this is that steps also must be taken to minimize the chance that any data has been altered outside of the LIMS audit trail system. The pragmatic effect of this is that data integrity standards, such as the FDA's 21 CFR Part 11 are even more stringently applied. This effectively means, or should mean, that generic file transfers, such as an instrument dumping an output file into a polled directory that is later imported into the LIMS is not allowed, as the data file can conceivably be altered between its export and import. A more secure process, such as a handshake system, possibly in a virtual private network (VPN), should be required.

A quote attributed to the criminalist Stuart Kind states that 'Interfaces alter cases'. (5) In the original context, this referred to the possibility, some would even say likelihood, of data being altered anytime it was transcribed from one system to another. Thus, the fewer manual data transfers in your system, the better-off you are. This approach can be taken further by selecting a system that supports the National Institute of Justice's (NIJ) Forensic Information Data Exchange (HDEX) project. (6)

It is unfortunate, but a reality, that the quality of forensic laboratories is highly variable. The National Academy of Sciences report on the state of forensic laboratories in the United States makes that clear. (7,8) While DNA testing is currently highly certified, thanks to initiatives such as Technical Working Group on DNA Analysis Methods (TWGDAM) and the DNA Advisory Board (DAB) administered by the FBI. (9) In other areas, ISO/IEC/EN 17025 General Requirements for the Competence of Calibration and Testing Laboratories is one of the more widely referenced certification standards. (2) In addition to all of its other benefits, a properly selected LIMS should aid in this reform by simplifying the lab's ability to track the certification and training of its employees and to provide the tracking data required for compliance with these other standards.

A less well-appreciated function of a good forensic LIMS is that, while it enhances communication of test results to the designated receiving parties, be they investigators, prosecutors or defenders, it also helps isolate the analysts from any interpretive pressures. Dr. Itiel Dror of the University of Southampton has shown how interaction between the evidence collectors, investigators and analysts can lead to an unconscious confirmation bias, (10) which a LIMS can help prevent. This bias can lead analysts to see patterns that are not there or can encourage them to force their results into a particular interpretation. This really shouldn't be as much of a surprise as it seems to be to some people--as far back as 1891, Sherlock Holmes was reminding people that "It is a capital mistake to theorize before one has data. Insensibly, one begins to twist facts to suit theories, instead of theories to suit facts." (11) This is a very good lesson to keep in mind, whether interpreting evidence or purchasing a LIMS.

To wrap up, the results of forensic laboratories are very important, both for identifying and convicting the guilty, as well as exonerating the innocent. A good forensic LIMS can significantly aid that process. To qualify as good, it needs to be both flexible and rigorous, with a very detailed audit trail. Its interface should be such that it is easy to review the consolidated case evidence, so that you can build on their synergy while protecting the analysts from biasing their interpretations.

A forensic LIMS should support flexible instrument interfacing, but in such a way as to maintain the data's integrity. It also should track employee qualifications and certifications to help ensure the validity of generated data. In summary, proper forensic LIMS selection (or any LIMS selection for that matter) requires that you carefully review your needs and processes, as well as why your processes are such as they are. Collect your data first and ALWAYS question your assumptions.


(1.) Denmark, A. & Mount, M. "Crime Lab Design" Lab Manager Magazine 5, 34-39 (2010).

(2.) Blackman, G. "Criminal Investigations" Scientific Computing World 16-18 (2009).

(3.) Hendrickson, A., Mennecke, B., Scheibe, K. & Town send, A. Laboratory information Management Systems for Forensic Laboratories: A White Paper for Directors and Decision Makers. 177 (Ames Laboratory (AMES), Ames, IA: Ames, IA 50011, 2005). Requirements_and_Executive_Summary_Final.pdf

(4.) Cowan, C. & Schwandt, M. Consideration in Adopting Large Scale Automation For The Forensic Laboratory," Forensic Magazine (2009).

(5.) JusticeTrax: Video--Quality Assurance Auditing in a Forensic LIMS. (2009).

(6.) Tech Shorts: Technology News Summary. JUSTNET (2009).

(7.) Strengthening Forensic Science in the United States: A Path Forward. (The National Academies Press: Washington, DC, 2009).

(8.) Tulsi, B. "Perspective On: A Forensic Crime Lab," Lab Manager Magazine 5, 38-41 (2010).

(9.) Reeder, D.J., Calandro, L. & Schades, L. "The Evolution of Forensic DNA Laboratories and The Challenges They Face" Forensic Magazine (2007).

(10.) Dror, I. "Biased brains" Police Review 20-23 (2008).

(11.) Doyle, S.A.C. A Scandal in Bohemia. The Adventures of Sherlock Holmes 448 (2009). 19thC/?view=usa&ci=9780199536955

John Joyce is a laboratory informatics specialist based in Richmond, VA. He may be reached at

John R. Joyce, Ph.D.
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Title Annotation:INFORMATICS
Author:Joyce, John R.
Publication:Scientific Computing
Date:May 1, 2011
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