Blog Post 2: Technological Aspect of Genetic Genealogy

The second of Jeanbaptise’s blogs about genealogy and the Bear Brook Case for her senior project applied piece.

Blog Post 2: Technological Aspect of Genetic Genealogy

As I am beginning to learn more and more about genetic genealogy, I’m realizing that there are many technical aspects to it. It’s really not that simple actually. With DNA testing and databases you can get a basic understanding of a person, meaning you can see what their name is, where they are from and more advanced information about them. For example, with the Bear Brook case, Terry Rasmussen and the use of his other Chameleon names investigators were able to arrest him because of DNA testing. Terry went by multiple names, that is why he was also known as the “ chameleon killer”. The names that he has used in the past were Robert “Bob” Evans, Curtis Mayo Kimball, Larry Vanner, Gordon Jenson and Gerry Mockerman. His identities were all identified in June 2019.

Before getting into the process of matching names with faces, investigators have to take a simple DNA test. It’s quite simple. First, the individual that is taking the DNA test, must wash their hands to get any excess grease off their hands so the test can be accurate.  Once their hands are dry, their thumb gets put onto an ink pad. Lastly once their thumb is inked, their thumb gets put into a fingerprint card.

When finding individuals that are unknown, law enforcement enters DNA  into data tests that were taken on the individual and enters it into a CODIS database. According to “”, CODIS stands for a combined DNA index system. It is a national database that has multiple indexes that contain DNA profiles of convicted offenders, profiles for missing people, as well as profiles for unsolved cases. CODIS is indeed an important tool for investigators because it was designed to compare a person’s DNA to a DNA test that may already be in the CODIS database. Once a match is matched together, laboratories meet together to verify the matches to ensure they are the proper person for the match. 

In the Bear Brook case, it’s uncertain if the victims and even the chameleon killer himself was put into the specific CODIS, but overall they were put into databases to match their identities. 

I did not think that DNA testing was as complicated as it seemed, but I was able to get a better understanding of DNA testing and different databases that are used in not only the Bear Brook case, but thousands of other cases in the U.S today. As I was speaking to Sergeant Matthew Koehler, he informed me that so far since the Bear Brook case, he has not worked on any cases using this new technology, but he is sure that in the future he definitely will. As said in my previous blog, genetic genealogy will definitely evolve and become more advanced in the future. 

Thank you for reading! In my last and final blog, I will be discussing how long it takes to find people, specifically the killer and the victims using genetic genealogy. Stay tuned!