Reported / Citable
Background
In 1995 and 1998, Kevin Konther committed two violent sexual assaults in Lake Forest. Police collected DNA from both victims, uploaded the profiles to the FBI’s CODIS database, and found no matches. The cases went cold for more than two decades. In 2018, investigators turned to investigative genetic genealogy — a technique that combines detailed DNA analysis with genealogical research — to crack the cold cases.
Investigators sent the crime-scene DNA to a private lab, which converted it into a detailed single-nucleotide polymorphism (SNP) profile. That profile was uploaded to publicly available genealogy websites, where it matched relatives of Konther and his identical twin brother. The FBI concluded one of the twins was the likely offender. Police then collected DNA from trash outside both brothers’ homes and confirmed a match. Konther was arrested and, in secretly recorded jailhouse conversations with his brother, essentially confessed. A jury convicted him of two forcible rapes, lewd conduct with a child, and related sex offenses. The trial court sentenced him to 140 years to life.
Before trial, Konther moved to suppress all evidence flowing from the IGG analysis, arguing that converting the crime-scene DNA into a comprehensive SNP profile and uploading it to genealogy databases constituted a Fourth Amendment “search” requiring a warrant. The trial court disagreed and denied the motion, and the Court of Appeal accepted the case for partial publication specifically because no prior California published decision had addressed IGG.
The Court’s Holding
The Fourth District Court of Appeal affirmed the denial of suppression in a published opinion. The court applied the foundational Fourth Amendment rule that a person has no reasonable expectation of privacy in abandoned property. When Konther raped his victims, he left semen behind — and with it, whatever genetic information it contained. The court agreed with the trial court’s conclusion that there is no “reasonable expectation of privacy for a semen sample left at a crime scene during the commission of a crime.”
Konther’s more sophisticated argument was that even if the semen itself was abandoned, the comprehensive genetic profile created from it — an SNP file with hundreds of thousands of data points, vastly more revealing than a standard CODIS fingerprint-like profile — implicates a distinct privacy interest. The court rejected this framing. The abandonment doctrine does not turn on what analysis is later performed on the abandoned material; it turns on whether the person retained a reasonable expectation of privacy in the property at the time of collection. Konther had no such expectation. The court followed the Minnesota Supreme Court’s reasoning in State v. Carbo (Minn. 2024), which reached the same result on materially identical facts.
The court also noted that its conclusion is consistent with a prior California appellate decision applying the abandonment doctrine to DNA evidence generally, People v. Gallego (2010). Because the IGG analysis was not a search, no warrant was required and the suppression motion was properly denied.
Key Takeaways
- This is the first California published opinion squarely holding that investigative genetic genealogy (IGG) does not constitute a Fourth Amendment search when the source DNA was abandoned at a crime scene.
- The abandonment analysis focuses on whether the person had a reasonable expectation of privacy in the physical material at the time it was collected — not on what type of analysis law enforcement later performs on it.
- Criminals who leave biological material at a crime scene (blood, semen, saliva, skin cells) have no Fourth Amendment protection over any genetic analysis of that material, including comprehensive SNP profiling for genealogical database searching.
- IGG has now been validated as a cold-case tool in California; law enforcement agencies can use it without a warrant when working from crime-scene samples, subject to any applicable state statutory limitations on genealogy databases.
- Defense challenges to IGG evidence must now focus on non-Fourth Amendment grounds — e.g., chain of custody, lab reliability, or whether any statutory rules governing commercial genealogy databases were followed — rather than constitutional suppression.
Why It Matters
Investigative genetic genealogy has already solved hundreds of cold cases nationwide, including the Golden State Killer prosecution, and its use is growing rapidly. Before this decision, California had no published ruling on whether IGG implicates the Fourth Amendment. Defense attorneys and civil liberties advocates had argued that the technique’s power — it can identify suspects through distant relatives, effectively mapping an entire family’s genetic tree — warranted a higher constitutional threshold than ordinary DNA fingerprinting. This decision rejects that argument at the threshold: once biological material is left at a crime scene, the perpetrator forfeits Fourth Amendment protection over whatever genetic information it contains.
For California practitioners, the ruling signals that suppression motions attacking IGG on pure Fourth Amendment grounds will not succeed when the source material was abandoned at a crime scene. Cold case investigations using IGG should now be on firmer footing in California courts. The more consequential regulatory questions — such as whether law enforcement’s use of consumer genealogy databases raises privacy or statutory concerns separate from the Constitution — remain open and are likely to be the next battleground as the technology becomes more widespread.