DNA databases have been very effective at developing investigative leads, providing new suspects for unsolved forensic cases. To date, the majority of forensic laboratories utilize DNA databases with direct matching, where forensic profiles found at crime scenes are compared to profiles from known individuals and must match exactly. Expanding the size of a law enforcement DNA database can be accomplished by increasing the number and type of qualifying offenses and by including arrestees.
In his presentation at ISHI 33, Ray Wickenheiser will introduce A new technique termed Enhanced DNA Indirect Matching (EDIM). EDIM involves expanding the DNA profile of the forensic samples beyond the core CODIS (Combined DNA Index System) autosomal loci. This expanded profile permits the strategic use of search keys. Search keys are areas of DNA which are inherited in known biological and statistical patterns, which enhance the opportunity to locate relatives. Potentially related candidate profiles are then further evaluated through kinship analysis, to determine whether the candidate is more likely a close or distant relative, or merely a coincidental search key link.
We chatted with Ray to discuss the current state of DNA databases and how expanding the types of qualifying offenses could be more cost effective. We also examine the concepts of a universal database, explore EDIM, and get to know Ray a bit better.
How are most DNA databases currently used? How might expanding the types of qualifying offenses and arrestees be more cost effective?
Forensic DNA databases currently include an index of known samples that are collected under a set of rules that are established by the elected officials in a particular jurisdiction. In the US, the qualifying offenses for inclusion in the database of known individuals are determined by the states, as well as whether to include arrested individuals or not. This set of known samples is searched against DNA profiles from samples that occur at a crime scene, known as forensic samples. Separate indexes in the database contain profiles from known samples and forensic samples. The forensic profiles must also have a set of qualifying attributes, such as being deposited during the commission of a crime and likely to have originated from the putative perpetrator. This is exclusive of missing persons indices, which are held separately.
Increasing the number of known samples that a forensic sample is compared against increases the chance of finding a match to a potential perpetrator. Collecting known samples owed by individuals who have committed qualifying offenses and not submitted a sample is also an opportunity to increase database effectiveness. Collecting samples owed can be very time and resource consuming, however. Therefore, the collection of a DNA sample could be connected to another type of societal privilege, such as renewing a driver’s license or obtaining a passport, so a DNA sample owed can be collected as well as the correct person identified simultaneously. If this mechanism of DNA collection was established, expansion of qualifying offenses could be accomplished cost effectively, and used to collect samples owed or when an original collection failed to produce an acceptable DNA profile. In my presentation, I will show the very large savings from expanding database size.
What might a universal database look like?
Determining database size balances competing bioethical principles of public safety (larger databases) versus individual rights (smaller databases). In my representation I will discuss the concept of a universal database covered in my recent paper as a theoretically model to illustrate the potential cost savings of DNA databases if expanded to the largest crime saving potential:
A universal database of DNA could be created with samples taken with driver’s license applications, thereby providing known samples for comparison to the over 500,000 unmatched forensic samples in the US database to help solve those crimes.
Can you briefly explain the Enhanced DNA Indirect Matching (EDIM) concept that you’ll be introducing at ISHI?
The EDIM concept I will be discussing at ISHI will include using search keys beyond the autosomal STRs that are currently used in forensic laboratories to search DNA databases. Use of search keys in EDIM is an indirect matching technique used to find potential relatives of a perpetrator when a direct STR match has not occurred. While I will provide an example using Y-STRs, there are a large number of other potential search keys that include mtDNA, X chromosomes and SNPs which can be similarly used and combined to search for related individuals. Once potentially related individuals are found, traditional kinship testing can evaluate the possible biological relationship and provide an investigative lead, similar to that currently provided in familial searching or forensic investigative genetic genealogy.
How might using expanded potential search keys better accommodate technologies and techniques that are becoming more widely used in forensic laboratories? Are there any limitations?
Using different search keys and indirect matching fits very well with new technologies. As different areas of DNA are investigated, we discover more about what we have in common with others and where we are different. Using those areas of commonality to search for biologically related individuals increases our ability to use the inherited features of DNA to develop investigative leads to help solve crimes.
Challenges of expanding use of search keys and indirect matching comes in the form of privacy and bioethical concerns. This is because the technique searches individuals who did not commit the crime to use their biological relatedness to find a lead to the person who did deposit the forensic sample. We must be diligent having these discussions and design policies and procedures with appropriate safeguards to ensure these issues are properly addressed. Policy discussions for the application of technology should go hand in hand with its development.
What tips would you give to someone who is just starting out in the field of forensics, or what is the best advice that you’ve received?
The best advice that I have received is that we are scientists who are neutral and go where the data leads us. We develop and utilize methods that can shed light on who did and did not commit this crime. We must be objective, and let the data speak for itself.
If you had to pick one thing, what do you enjoy most about your job?
I really enjoy the passionate people who join our field of forensic science, bringing their energy, enthusiasm, and brilliance to help solve crime with objective science. We get to work with a great group of folks.
If you currently work in the lab, or have in the past, what’s the weirdest thing you’ve ever collected DNA from?
I have been blessed to have worked on a host of interesting cases, but if I had to pick one item, it would be a fragment of contact lens that I picked out of a full vacuum cleaner bag. The assailant had tricked the victim to enter a location where he assaulted and beat her, knocking out her contact lens in the process. She eventually escaped and was too afraid to report the crime until days later. Hence, no other associative evidence was available. Once the police attended the scene, it had been extensively cleaned. In an effort to corroborate her story, investigators submitted the vacuum cleaner bag to the forensic laboratory. Working with my colleagues, we were able to obtain a full DNA profile from a contact lens fragment located within the pile of debris. The major component of the mixed DNA profile matched her, and the suspect plead guilty just prior to trial.
If you could have dinner with anyone (dead or alive), who would it be? Why?
I would choose Dr. George Carmody, professor, forensic geneticist, and statistician. George was a great friend and colleague who could make the most complex concepts understandable, interesting, and fun. He had a passion for forensic science and loved getting out and meeting crime lab scientists and sharing his knowledge.
If you’ve attended ISHI in the past, what do you most enjoy about coming to the conference? If you haven’t, what are you most looking forward to?
I enjoy ISHI as it gets me out amongst many of the brightest and most passionate forensic DNA scientists, learning from them, and discussing cases, cases, cases. It is so much fun.
What’s one thing that others may not know about you?
I enjoy playing ice hockey and play in a hockey league and charity tournaments.
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