STR-Validator: Open Source, Free Software for Evaluating Validation Data in the Forensic Laboratory

Before an established method or procedure can be employed in a forensic laboratory, an internal validation must be completed to show that the method performs as expected. Guidelines for validation are outlined by the Scientific Working Group on DNA Analysis Methods (SWGDAM) and the European Network of Forensic Science Institutes (ENFSI) DNA Working Group. Validation experiments that meet these guidelines will demonstrate the sensitivity and reliability of a short tandem repeat (STR) typing multiplex system. After a lab completes these validation experiments, it will have sufficient data to determine the analytical and stochastic thresholds of the capillary electrophoresis (CE) instrument in combination with the amplification system, the impact of multiple contributors to a DNA sample and the limit of detection and accuracy of the assay.

Such forensic lab validations are time consuming and can be intimidating, and the requirement to validate new technologies and systems is often seen as a deterrent to the adoption of new technologies or improved chemistries in a forensics laboratories. Any tools or tips that can reduce the barrier of validation, may also help the field of DNA forensics implement new technologies more quickly.

On October 1, Oskar Hansson, from the Department of Forensic Medical Services at Oslo University Hospital, will be leading a workshop entitled “Efficient Validation Using STR-Validator” as part of ISHI 28. This workshop introduces the free, open-source STR-Validator software tool that is designed to assist forensic laboratories in the evaluation of validation data. STR-validator is a free and open source R-package developed mainly for internal validation of forensic STR DNA typing kit. However, it is equally suited for validation of other methods and instruments, or for process control. The graphical user interface of the software enables easy analysis of data exported from software programs like GeneMapper® software, without any knowledge about R commands. The software also provides convenient functions to import, view, edit, and export data. After completed analysis, the results, plots, heat-maps, and data can be saved for easy access. Currently, analysis modules for stutter, balance, drop-out, concordance, mixtures, precision, pull-up, result types, and analytical threshold are available. STR-validator can greatly increase the speed of validation by reducing the time and effort needed for analysis of the validation data.

The workshop will include lectures and demonstrations to introduce STR-Validator as an efficient tool for the analysis of validation data in accordance with ENFSI recommendations and SWGDAM guidelines. This workshop is suitable for DNA analysts, technicians and QA/QC managers.

Have you registered for ISHI 28 in Seattle? Check it out. This year’s panel discussion will take up the topic of familial searching. Preregister for workshops. Read speaker bios.

Interested in more tips for smoother validation in your lab? This blog has several suggestions.

Promega Third Party Forensic-Grade Certification

Promega has become the first major forensic manufacturer to achieve third party certification of the published ISO 18385 standard to minimize the risk of human DNA contamination in products used to collect, store and analyze biological material for forensic purposes.

On February 2, 2016, ISO 18385:2016 was published as the first international standard specific to the forensic manufacturing community. Since the standard was published, companies have begun to self-declare that they comply with the ISO standard. Some companies have gone a step further and reached out to Certification Bodies to provide an unbiased and independent assessment their compliance to ISO18385 through a third-party audit.

When consumers see an ‘ISO 18385 Forensic Grade’ labeled product, it should inspire confidence that the product was produced in accordance with a minimum set of criteria common to all manufacturers.

So what are you actually getting in a Forensic Grade labeled product? Continue reading

Promega Tech Tours 2017: The Power to Solve for the Forensic Community

Governor John Bel Edwards of Louisiana made an appearance at the Promega Technology Tour in Baton Rouge. Pictures courtesy of Forensic Scientists at the Louisiana State Police.

2017 finds Promega on the road visiting cities all across the United States. This year we are presenting workshops from leaders in the forensics community on topics like maximizing success with challenging samples, improving laboratory efficiency and reducing backlogs, and new tools and technologies for the forensics laboratory. This highly popular workshop series is a great way to learn from your peers about new techniques and workflows and network with other forensics experts in your region.

There are several more tours left between now and the end of 2017. Find out if we are coming to a city near you and register today!

Meet Jonelle Thompson, Validation Services Manager for the Spectrum CE Instrument

29160613_lPromega will soon introduce the Spectrum CE System for forensic and paternity analysis. Building this system requires the efforts of many people from many disciplines—from our customers who have told us their needs to the engineers and scientists building the instrument and ensuring its performance. Periodically we will introduce our Promega Connections readers to a team member so that you can have a sneak peak and behind-the-scenes look at Spectrum CE System  and the people who are creating it (of course if you truly want to be the first to know, sign up at www.promega.com/spectrum to receive regular, exclusive updates about Spectrum CE).

Today we introduce Jonelle Thompson, Validation Services Manager. Continue reading

Catching a Child Abuser in Five Days

ishi_27jpg

Next week, forensic analysts from all over the world will gather in Minneapolis for the 27th  International Symposium on Human Identification (ISHI). So today, we’d like to share one story from a forensics lab that highlights the importance of collaboration, knowledge-sharing and technology development–since that is what ISHI is all about. 

Crimes against children are especially heinous, and it is vitally important that the offenders are removed from the streets as soon as possible. In today’s blog, Sarah Chenoweth from the Anne Arundel County Crime Lab in Maryland describes a sexual assault case that was solved in just five days. Key to this speed were the collaboration between lab staff and state police, and the ability to quickly and reliably amplify DNA profiles from low-DNA samples. Thanks to the efforts of the investigators involved, parents in Maryland, and possibly nationwide, can sleep a little easier.

On Friday, February 5th, the Anne Arundel County Crime Lab was notified of a sex offense involving a 7-year-old victim. With our efficient DNA workflow, including use of the Fusion amplification kit with our 3500 Genetic Analyzer, we were able to identify the perpetrator in only five days. Continue reading

Addressing the Sexual Assault Kit Backlog: Defining the Problem, Creating Solutions

general tweet from USA article

This post was contributed by  guest blogger Tara Luther in the Genetic Identity group at Promega.

In July 2015, USA Today formed a partnership with journalists from over 75 Gannett-owned newspapers and TEGNA television stations to “perform the most detailed nationwide inventory of untested rape kits ever.” This article told the stories of rape victims who had lost hope of seeing the perpetrators of their assaults ever being brought to justice, even though DNA evidence was collected at the crime and was waiting to be analyzed.

The journalists working on this story uncovered more than 70,000 neglected rape kits in an open-records campaign that covered more than 1,000 police agencies. The story notes that “despite its scope, the agency-by-agency count cover[ed] a fraction of the nation’s 18,000 police departments, suggesting the number of untested rape kits reach[ed] into the hundreds of thousands.”

tweet 3The USA Today effort led not only to national reporting but also to many local stories as well.

EndTheBackLog.org is a program sponsored by the Joyful Heart Foundation aimed at getting policy makers and prosecutors to address the large numbers of untested rape kits in the United States. They hope by researching to identify the extent of the backlog and publicizing that research they will begin a dialog at local, state and national levels that will lead to solutions for addressing it. The USA Today story and local stories have grown out of their efforts to call attention to this problem. Continue reading

Discovering the Truth About the Dozier School for Boys

Dozier School for Boys gravesite

Photograph from The Tampa Bay Times

The Dozier School for Boys had cemeteries instead of playgrounds.

The stories of abuses that took place at the reformative school in Marianna, Florida are nothing short of a plot for the TV series American Horror Story. The beatings and other punishments administered to students throughout the school’s 111-year history contributed to the deaths for some of the nearly 100 deceased.

A 2010 investigation by the Florida Department of Law Enforcement did not lead to criminal charges against the school because there was “no tangible physical evidence for allegations of physical and sexual abuse.” The full report is available on The White House Boys Survivors Organization’s website, a name derived from the shed where the boys were beaten with wooden panels and leather straps. At the time, only 32 unmarked graves were known in the school’s cemetery. Continue reading

Familial DNA Searching for Criminal Forensics: Q&A

When DNA evidence is collected at a crime scene, submitting the sample for a search within a DNA database does not always identify a profile match. There is a way to extend that search and generate leads, called familial searching (FS). FS is used to identify close biological relatives of an unidentified DNA profile obtained as evidence. The basic premise is that DNA profiles of immediate family members, such as siblings, parents, or children, are likely to have more alleles in common than unrelated individuals. These familial profile matches can generate new investigative leads for law enforcement.

Currently, a few states are using FS under their state database laws, although none explicitly permit FS. Many agencies have yet to adopt policies related to FS, even though it has been found to be as effective as CODIS for identifying sources of evidence. The absence of clear ethical guidelines and policy regarding how to properly utilize FS prevents many local and state jurisdictions from adopting this investigational tool.

In order to address concerns and existing policies related to FS and to guide policy decisions by agencies implementing FS, the National Institute of Justice (NIJ) issued the report Familial DNA Searching: Current Approaches in January 2015. The goal of the report was to provide information to policy makers, law enforcement officials, forensic laboratory practitioners, and legal professionals about how FS is being applied within the criminal justice realm.

Mr. Rock Harmon, former prosecutor

Mr. Rockne Harmon, former prosecutor

 

Answers to the following questions about FS were provided by Mr. Rockne Harmon, a retired former prosecutor and member of the team that produced the report for the National Institute of Justice.

 

What is familial DNA searching?

Familial searching (FS) is an additional search of a DNA profile in a law enforcement DNA database that is conducted after a routine search fails to identify any profile matches. The FS process attempts to provide investigative leads to agencies engaged in the pursuit of justice by identifying a close biological relative of the source of the unknown forensic profile obtained from crime scene evidence. Continue reading

Wanted: The Tomb of the Father of Modern Astronomy

What do Swedish war booty, the Frombork Cathedral in Poland, and Napoleon all have in common? Answer: Nicolaus Copernicus. While much is known about the cleric and astronomer, the location of his burial site and the identity of his possible remains were cloaked in mystery. Over the last 200 years, many have searched for Copernicus’s grave including Napoleon in 1807. While it is known the astronomer was buried at Frombork Cathedral in 1543, there are over 100 unmarked tombs; as a result, searchers have walked away frustrated and empty handed. Continue reading