Investigative genetic genealogy

There are more uses to investigative forensic genealogy than cold cases or cases otherwise deemed "unsolvable" by law enforcement. Natural disasters such as floods, wildfires, earthquakes are all prime examples of scenarios where gene-matching can be utilized. In instances where the body is unidentifiable by standard means, such as facial recognition or dental records, genetic technology can be used.

Law enforcement investigators have used the technique to identify nearly 40 women as the mothers of newborn infants who were found dead around the country, most of them decades ago. In most of the cases reviewed by The New York Times, women who were matched by DNA to a dead newborn were charged with murder. Some of the women who have been identified in these Baby Doe cases say they did not know they were pregnant until they went into labor. Some of the women who have been charged told the police their baby was stillborn. At least two women among the dozens of cases reviewed by The New York Times took their own lives after being approached by investigators armed with DNA evidence. Some were sentenced to decades in prison, while others got lighter sentences, often after pleading guilty to lesser charges like manslaughter. A handful of the women avoided prison time altogether. Civil rights advocates, doctors and defense lawyers say the new technique is raising questions that the courts are not yet prepared to answer.

A number of living doe situations have also been solved this way. There is push to provide more resources for DNA to be offered when there is a need to identify a child who has been trafficked, or an adult who was trafficked at a young age.

Agencies that fall under the US Department of Justice, who have jurisdiction on the case(s) and/or person(s), can utilize forensic genetic genealogical DNA analysis and searching, FGGS for short. The DOJ published an interim policy in 2019 that sets parameters for law enforcement's use of FGGS, though it only provides internal guidance and does not limit the DOJ's investigative actions that would otherwise be lawful even if in violation of the policy. For example, FBI investigators in the 2022 Idaho student murders allegedly skirted the DOJ policy in pursuit of the suspect.

The use of investigative genetic genealogy has been central in numerous high-profile cases, namely in the identification and ultimate arrest of Joseph DeAngelo, the Golden State Killer. Despite its apparent success, the growing use of genetic genealogy databases by law enforcement agencies has not avoided serious scrutiny. A year prior to the arrest of DeAngelo, an individual was wrongly identified as a suspect in the murder of Angie Dodge, an 18-year-old woman who was the victim of a 1996 murder in Idaho Falls, Idaho. Michael Usry was the subject of a police investigation that led to a court order requiring Ancestry.com to disclose the identity of a partial match to crime scene DNA. This partial match was Usry, who was ultimately cleared as a suspect after police secured a warrant for his DNA. This DNA test proved that he was not a full match to the perpetrator.

The use of genetic genealogy databases by investigators has initiated a debate over the Fourth Amendment implications of genealogy data. The Fourth Amendment states that a warrant is required in situations that violate an individual's reasonable expectations of privacy. Given the sensitivity of information within direct-to-consumer genealogy databases, particularly concerning medical traits, behavioral tendencies, ethnic background, and familial associations, consumers may assume that they have a reasonable expectation of privacy in the information contained within those databases. A number of legal scholars have argued similarly that the Fourth Amendment should protect privacy interests in the IGG process while balancing law enforcement's legitimate interest in solving crime. …

The US government's own Combined DNA Index System (CODIS) database is composed of forensic evidence accessible to local, state, and federal law enforcement officials. This database consists of genetic profiles of approximately 18 million different people, however these are limited to DNA samples from convicted felons and arrestees. Data on the racial distribution of profiles suggests that 8.6% of the entire African American population is present in the database compared to only 2% of the white population.

On the other hand, genetic profiles from direct-to-consumer databases and GEDMatch consist of 75% white individuals from Northern European descent. The vast overrepresentation of African American individuals within the CODIS database has rendered it relatively ineffective for solving serial murder and sexual assault cases, of which the majority of perpetrators are white. Based on data from 4,700 mass murderers, 57% of serial killers are white whereas only 29% are African American. It has been suggested that the use of investigative genetic genealogy, which relies heavily on databases like GEDMatch, would therefore help to reduce racial disparities in the current criminal justice system. However, in practice it has been found that the majority of victims identified through this technique were white.

The world's first Investigative Genetic Genealogy Center was launched at the Ramapo College of New Jersey in December of 2022. The center offers student workshops, certificate programs, and bootcamps for interested practitioners around the world. The center was established by David Gurney and Cairenn Binder. In June 2026, Cairenn Binder announced David Gurney's departure from the IGG center on the Ramapo College IGG website. Cairenn Binder was promoted to director of the IGG center and Monique Platt was hired to serve as director of the IGG certificate program.