In June 2026, a judge in Riverhead, New York, sentenced Rex Heuermann, a Manhattan architectural consultant, to life without parole for a string of murders that terrorised Long Island for more than a decade. He was connected to the deaths through DNA evidence and phone records and was arrested in 2023, and in April 2026 he pleaded guilty to killing eight women whose bodies were dumped along Gilgo Beach between the 1990s and roughly 2010. It is one of the only cases in recent memory that fits the classic, lurid template of the American serial killer, and the fact that it took genetic evidence and a cell phone trail to close it, rather than old fashioned legwork, is exactly the point. There is no law on the books, federal or state, that formally defines a serial killer. The most widely used definition comes out of a multidisciplinary symposium convened by the Federal Bureau of Investigation, which settled on the unlawful killing of two or more victims by the same offender in separate events, at different times, and deliberately dropped older requirements for a minimum of three victims or a cooling off period between crimes. Since the government does not keep an official count, the job has fallen to academics. The most cited resource is the Radford/FGCU Serial Killer Database, a project a Radford University psychology professor began building by hand in 1992 that has grown into the largest non-governmental database of its kind, tracking thousands of offenders and more than eleven thousand victims across the world. What that database and the criminologists who mine it agree on is stark. Serial homicide was not a constant feature of American life. It surged through the 1970s and peaked in the 1980s, a decade researchers estimate produced roughly 770 active serial killers in the United States, a number that dwarfs anything before or since. Peer reviewed research published in the journal Cogent Social Sciences found that the most recent decade studied contained barely half the share of cases that existed at that 1980s peak, roughly thirteen percent of the historical total compared with twenty seven percent concentrated in the eighties alone. Whatever produced Ted Bundy, John Wayne Gacy and the Green River Killer, it was a phenomenon of a particular moment, and that moment has passed. The timeline for genetic forensics does not line up neatly with that decline, and this is where the tidy DNA narrative starts to wobble. The FBI's Combined DNA Index System, known as CODIS, began life as a pilot software project in 1990 serving just fourteen state and local laboratories. The DNA Identification Act of 1994 gave the Bureau formal authority to build a National DNA Index System, but the index was not activated until October 1998, and even then it launched with only eight states contributing profiles before expanding nationwide. By the time CODIS was a functioning national tool in the early 2000s, the serial killer decline that criminologists point to was already well underway, having started its downward slide more than a decade earlier. DNA did not arrive in time to have caused the initial collapse in numbers, whatever role it has played since. Criminologists offer a menu of competing, and probably complementary, explanations for what actually happened. Northeastern University's James Alan Fox, who has studied the phenomenon for decades, points to a simple loss of opportunity: people stopped hitchhiking, parents got more protective, and the pool of easily isolated, trusting strangers that killers like Bundy exploited largely dried up. Fox has also told Northeastern Global News that surveillance cameras and cellphones' GPS (Global Positioning System) tracking capabilities make it harder for serial killers to abduct victims in the first place, a mundane technological shift with an outsized effect. Fox and his frequent co-author Jack Levin have separately argued that the explosive growth of the American prison population from the 1980s onward may have taken potential offenders off the streets before they ever escalated. None of these explanations require DNA to do any work at all. The cleanest version of the decline story also runs into a stubborn complication: clearance rates for homicide have been falling, not rising, for decades. The Murder Accountability Project, founded by former journalist Thomas Hargrove, has tracked FBI figures showing that only fifty one percent of homicides were solved in 2021, down from a historical clearance rate closer to seventy percent. Hargrove's organisation attributes the slide to a failure to give necessary resources to local police and a failure of political will by elected leaders to prioritise major crime investigations. If fewer murders are being solved overall, some unknown fraction of what looks like a decline in serial killers may really be a decline in the ability to link scattered killings to a single offender in the first place, not a decline in the killing itself. Meanwhile, genetic genealogy, a distinct and much newer technique from routine CODIS matching, keeps reopening cases that were written off as unsolvable. Investigators have used it to identify cold case victims and suspects decades after the fact, including a Pennsylvania case that took fifty eight years to crack and, as recently as July 2026, the identification of a cold case victim known as Chelsea Jane Doe after nearly twenty six years. A Chevy Chase, Maryland, murder from 2001 sat unresolved for more than two decades before genetic genealogy pointed investigators to a suspect. Each of these solves is technically a decades-old serial or single killer being retroactively confirmed, which means the historical statistics criminologists rely on are still being revised upward in real time, long after the fact.
🔬 science
Did DNA Kill The Killers?
The men who once terrorised entire regions for years at a time have all but vanished from American life, and the last one caught made national headlines for how he was caught, not just what he did. A swab of saliva and a cell phone log did more to end his career than any detective ever could, but the tidy story that DNA (deoxyribonucleic acid) wiped out serial murder does not survive contact with the evidence.
My Take
The honest answer is that DNA did not kill the serial killer, but it did make the ones who remain almost impossible to sustain for long. The real killer of the golden age offender was a mundane cocktail of prison expansion, a wired and camera-saturated public, and the death of hitchhiking culture, all of which had already done their work before CODIS was a functioning national system in the early 2000s. Genetic forensics arrived after the party was mostly over and then did something arguably more important: it started retroactively hunting down the guests who thought they had gotten away with it. That is the more interesting story than the one about a magic forensic bullet, and it is also the more unsettling one. If clearance rates are genuinely falling while unsolved cold cases keep cracking open decades later thanks to genetic genealogy, the tidy graph showing serial murder in freefall since the 1980s should be read as a floor, not a ceiling. Somewhere in a police evidence locker there is almost certainly another Rex Heuermann, active for years, connected to nothing yet, waiting for a distant cousin to spit into a tube for a genealogy hobby website. The Gilgo Beach case is the clearest proof of concept for where this is heading. It was not DNA alone that ended Heuermann's run; it was DNA combined with cell phone records, the same surveillance infrastructure Fox credits with shrinking the pool of victims in the first place. The future of catching whatever is left of America's serial killers looks less like a single forensic breakthrough and more like a pincer movement between genetic science and the digital exhaust every person now leaves behind them.
What Happens Next
Expect more decades-old cases to fall in the coming months as genetic genealogy labs work through backlogs of preserved evidence from the 1960s through the 1990s, the exact window when serial murder was at its historical peak and when biological evidence was collected but could not yet be meaningfully analysed. Genealogists like those who worked the Golden State Killer case in 2018 have built a template that smaller police departments are now replicating with commercial genealogy databases such as GEDmatch, meaning victims currently filed as isolated unsolved homicides may eventually be reclassified as part of a serial pattern nobody had connected. On the policy side, watch for continued friction over consumer DNA privacy as more genealogy companies face law enforcement requests, a debate that will only intensify every time a high profile arrest like Heuermann's makes headlines. Separately, the Murder Accountability Project's clearance rate data is likely to keep pressuring city police departments and local politicians to justify why homicide investigation resources have not kept pace with population growth, an argument that will resurface every time a new cold case DNA solve embarrasses a department that let a file gather dust for twenty or thirty years.
What History Tells Us
The 1970s and 1980s produced the offenders who still define the public image of the serial killer, Bundy, Gacy, the Green River Killer, at a moment when hitchhiking was common, missing persons cases involving transient victims drew little sustained investigative attention, and no national system existed to connect a murder in one jurisdiction to a similar one in another. That same period also saw the beginning of a historic expansion of the American prison population, a shift some criminologists believe removed potential offenders from circulation before DNA forensics or national databases ever existed to catch them.