Investigative Genetic Genealogy and Criminalistics – What is the Future?

Investigative Genetic Genealogy (IGG) has been amazing in solving both cold and recent cases and for exonerating the innocent. Each day, another once-thought-to-be-intractable case is solved using this new-to-forensics means of human identification. We live in exciting times for forensic identification!

Despite, or because of, this success, the use of genetic genealogical data for forensic casework has brought up issues – the most obvious relating to personal privacy versus public safety – that is, the use of personal genetic data for the common good. Yet more concerns arise at each level of forensic investigation as we try to make practical use of IGG autosomal SNP analysis within an infrastructure of the better understood use of forensic STR analyses and databases such as CODIS for investigative lead generation.

The science of SNP genotyping on which IGG depends arose from the biomedical industry; the practical application of that science to human identification came from the genealogy community’s efforts to solve cases of misattributed paternity. Consequently, IGG has developed for the most part outside of the conventional framework of the forensic community, without the legal and scientific input that has helped to define current crime lab standards, policies, and procedures, much like the historical applications of RFLP, PCR, reverse dot blots, Sanger sequencing, and capillary electrophoresis (CE) to forensic genetics.

Over the last three decades, the path of a DNA sample collected from a crime scene has been relatively straightforward. An item is submitted to a crime lab for comparison to a known suspect, and/or, if eligible, for upload to forensic DNA databases for one-to-many queries against STR profiles from suspects, arrestees, convicted offenders, and solve and unsolved cases, depending on the specifics of a jurisdiction. Where familial searching is practiced, a search is performed for partial hits to immediate relatives. Direct comparison to a reference sample is warranted if a CODIS or a familial hit is achieved.

With the advent of IGG, however, the decision-making process has become more complex due to
alternate pathways for crime scene DNA analyses. CE and NGS methods in the hands of crime labs are well defined; whether a sample is eligible for CODIS upload is made based on protocol. However, the technology required to generate a genetic genealogy SNP profile, whether by whole genome sequencing, microarray or targeted NGS, is currently in the hands of private labs, not for profit labs and genetic genealogy companies. Decisions on whether a sample could or should be used for IGG analysis is based on emerging sample quantity and quality guidelines, such as those stated in the DOJ Interim Policy on Forensic Genetic Genealogy, and are currently made by law enforcement and legal authorities with input from those labs and companies.

We present an overview of how the two infrastructures–CE-based typing and SNP-based IGG –presently co-exist with less than optimum overlap, along with short, medium, and long term views on how they could be made more compatible, and perhaps combined into a less complex, and more efficient system. We also discuss the development of an IGG Think Tank open to all members of the community who have an interest in streamlining the process for IGG casework. We welcome input from law enforcement agencies, both crime labs and private labs, suppliers, the legal community, and genetic genealogists.