DNA Genealogical Comparison Can Be Used to Find Suspects

Texas prosecutors take sex crimes seriously and will pursue the maximum penalty against perpetrators. Age does not protect an assailant from criminal conviction, which a Dallas resident, 74 years old, learned in August 2020 when he was arrested on serial rapist charges. The man (called “the August suspect” in this blog) stands accused of being one of the (now) four identified serial rapists who terrorized the Dallas area in the 1970s and 1980s. He is the leading suspect in a total of six sexual assault cases: four in Dallas and two in Louisiana.

In the 1980s, several Dallas women reported waking up to find a man in their homes who tied them up, covered their heads, raped them at gunpoint, and stole their jewelry and money. Police collected DNA from the assaults but had no matches in the DNA database, CODIS. The August suspect served four years in prison for an Arkansas rape in 1973, but his DNA was not collected in that case. At that time, the requirement to maintain perpetrators’ DNA in the database had not yet been implemented, which allowed him to quietly move to Texas.

In 2005, the Dallas Police Department launched a new program to solve sexual assault cases using DNA technology. The program was called “Forensic Genetic Genealogy Analysis.” This DNA process is well known for the capture of the notorious Golden State Killer in California in April 2018.

Forensic Genetic Genealogy utilizes nucleotide polymorphisms to compare a DNA sample from a suspect to the DNA of a close relative for shared blocks, which are essentially similarities between relatives. Closer relatives have more blocks in common, while distant relatives have fewer blocks in common. Scientists can estimate how close in relation the suspect and the family member are and can begin to narrow in on the identity of the suspect.

It is not currently known how the August suspect’s DNA was traced, but the Golden State Killer was found using online family trees dating back to the 1800’s. With the increased use of home DNA lineage kits, more DNA is available from family trees, which gives investigators more opportunities to compare a suspect’s DNA to possible relatives. One of the August suspect’s victims requested the DNA from her rape kit be compared to genealogy websites using this method. Her request and the subsequent comparisons led to matches in the other three rape cases in Dallas and two more in Shreveport, Louisiana.

Texas has a ten-year statute of limitations for sex crimes after the DNA is tested, meaning a person cannot be charged with a crime if the DNA was tested more than ten years ago. There are many exceptions to this limitation. Egregious sex crimes against a child or disabled victim have no statute of limitations. Other sex crimes involving children may have a 20-year limit. In this case, the relevant issue is that when there are five or more victims of similar assaults by the perpetrator, there is no statute of limitations. The August suspect can be charged for all of these crimes because there are at least six victims.

If you have been accused of sexual assault or another crime, contact [law-firm] by calling (972) 369-0577. You need an attorney to competently represent you against complicated DNA advancements and exceptions to the law that can threaten your freedom.

Written by: Rosenthal Kalabus & Therrian Last Updated : June 15, 2023