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DNA Technology Convicts a 64-Year-Old for Murdering a Teenager in 1982 (cnn.com) 78

"More than four decades after a teenager was murdered in California, DNA found on a discarded cigarette has helped authorities catch her killer," reports CNN: Sarah Geer, 13, was last seen leaving her friend's houseï in Cloverdale, California, on the evening of May 23, 1982. The next morning, a firefighter walking home from work found her body, the Sonoma County District Attorney's Office said in a news release... Her death was ruled a homicide, but due to the "limited forensic science of the day," no suspect was identified and the case went cold for decades, prosecutors said.

Nearly 44 years after Sarah's murder, a jury found James Unick, 64, guilty of killing her on February 13. It would have been the victim's 57th birthday, the Sonoma County District Attorney's Office told CNN. Genetic genealogy, which combines DNA evidence and traditional genealogy, helped match Unick's DNA from a cigarette butt to DNA found on Sarah's clothing, according to prosecutors... [The Cloverdale Police Department] said it had been in communication with a private investigation firm in late 2019 and had partnered with them in hopes the firm could revisit the case's evidence "with the latest technological advancements in cold case work...."

"The FBI, with its access to familial genealogical databases, concluded that the source of the DNA evidence collected from Sarah belonged to one of four brothers, including James Unick," prosecutors said. Once investigators narrowed down the list of suspects to the four Unick brothers, the FBI "conducted surveillance of the defendant and collected a discarded cigarette that he had been smoking," prosecutors said. A DNA analysis of the cigarette confirmed James Unick's DNA matched the 2003 profile, along with other DNA samples collected from Sarah's clothing the day she was killed.

In a statement, the county's district attorney "While 44 years is too long to wait, justice has finally been served..."

And the article points out that "In 2018, genetic genealogy led to the arrest of the Golden State Killer, and it has recently helped solve several other cold cases, including a 1974 murder in Wisconsin and a 1988 murder in Washington."
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DNA Technology Convicts a 64-Year-Old for Murdering a Teenager in 1982

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  • If DNA is the only evidence in the case, how do they know it's not a false positive?
    • ok, I read the article, and he admitted to having sex with the victim that night. Went to trial, the jury found him guilty.
      • I'm still not clear on how they proved strangulation from DNA evidence. Admitting to sex with victim sounds like a good defense to plant a seed of doubt.
        • Ultimately we'd have to ask the jury to know for sure, but he was definitely lying. Furthermore there were other witnesses who testified at the trial. You can probably get the transcript from the trial if it's really important to you, but I see no reason to believe justice wasn't served.
    • by Anonymous Coward

      How does one get a "false positive" from DNA? This isn't a yes or no test. Do you mean contamination from a third party?

      • by CommunityMember ( 6662188 ) on Saturday February 21, 2026 @10:58PM (#66003440)

        How does one get a "false positive" from DNA? This isn't a yes or no test. Do you mean contamination from a third party?

        Siblings can sometimes result in a match, and depending on the testing methodology (short strings), there can also be false positives. However, both are not exactly common with today's approaches of matching. Both (and other) possibilities can be brought up by the defense consul to try to create doubt in the juries minds in trial.

        • My understanding is that most testing methodologies can have false positives, it's just that some methodologies are extremely unlikely (like 1 in 100,000,000). If you apply such a test to the 10 people who were at the scene and get a match, you can be pretty confident that you have a legit match. If you apply it to all 300,000,000+ Americans and get a match... well, the only thing surprising about that would be if you only got 1 match!
      • by Tomahawk ( 1343 ) on Sunday February 22, 2026 @05:30AM (#66003702) Homepage

        It's a percentage of confidence.

        There was a case only last year where someone was released from prison many years after he was sent there because his DNA was a very very close match to the actual killer.

      • by XXongo ( 3986865 )

        How does one get a "false positive" from DNA? This isn't a yes or no test. Do you mean contamination from a third party?

        DNA testing is a statistical test. There is always the possibility of a false positive.

    • Experts or "experts".
  • No priors? (Score:4, Interesting)

    by backslashdot ( 95548 ) on Saturday February 21, 2026 @11:16PM (#66003458)

    These cold cases make me wonder, are there really a lot of "one and done" murderers out there? Did he commit other crimes and just keep getting away? I always thought these killers in unsolved cases would continue their behavior. Would be interesting to see if this guy felt any remorse or why he stopped. Makes me also wonder if many regular people can just snap given a certain set of circumstances.

    • These cold cases make me wonder, are there really a lot of "one and done" murderers out there? Did he commit other crimes and just keep getting away? I always thought these killers in unsolved cases would continue their behavior. Would be interesting to see if this guy felt any remorse or why he stopped. Makes me also wonder if many regular people can just snap given a certain set of circumstances.

      As you wonder about what “regular” people would do, here’s a brief reminder of context; you’re talking about a citizen living in a country that was forcibly drafting 18-year old men to fight and kill the Vietnamese enemy weeks after graduating high school, not even a decade prior to that crime happening.

      Ever wonder how many “regular” high school kids we forced to be killers rather early in life? Let’s also not forget all those “baby killer” warm welcom

      • This guy was way too young for Vietnam or even the draft.
        • This guy was way too young for Vietnam or even the draft.

          He was likely raised by the ones that were, and certainly grew up in a society full of war vets. Korea wasn’t far behind Vietnam, and we drafted during both.

          And quite honestly, a 13-year old killer isn’t anywhere near the definition of normal or regular. Age alone makes the argument a bit moot. No one would argue that was a troubled mind that thankfully didn’t develop a taste for more at that young age.

          • Re:draft, Vietnam (Score:5, Informative)

            by CaptQuark ( 2706165 ) on Sunday February 22, 2026 @02:15AM (#66003590)

            He was likely raised by the ones that were, and certainly grew up in a society full of war vets. Korea wasn't far behind Vietnam, and we drafted during both.

            If you're going to throw facts around to support your point, at least get them right.

            Korean War ~~ June 25, 1950 - July 27, 1953
            Vietnam War ~~ November 1, 1955 - April 30, 1975
            U.S. military All-Volunteer Force established on July 1, 1973

            If James Unick was born in 1961 he would have been 13 when the military eliminated the draft. The murder happened in 1982, which was 7 years after the Vietnam War ended.

            You could just as easily attribute his mental state on veganism, homosexuality, the hippy movement, drug usage, or lead in school drinking fountains. There is no evidence of any of those things. Trying to blame his mental state on disapproval of the Vietnam War is just you projecting your opinions.

            • He was likely raised by the ones that were, and certainly grew up in a society full of war vets. Korea wasn't far behind Vietnam, and we drafted during both.

              If you're going to throw facts around to support your point, at least get them right.

              Korean War ~~ June 25, 1950 - July 27, 1953 Vietnam War ~~ November 1, 1955 - April 30, 1975 U.S. military All-Volunteer Force established on July 1, 1973

              If James Unick was born in 1961 he would have been 13 when the military eliminated the draft. The murder happened in 1982, which was 7 years after the Vietnam War ended.

              You could just as easily attribute his mental state on veganism, homosexuality, the hippy movement, drug usage, or lead in school drinking fountains. There is no evidence of any of those things. Trying to blame his mental state on disapproval of the Vietnam War is just you projecting your opinions.

              I merely confirmed it was a different world to grow up in back then. As anyone who did knows. I (GenX) grew up under the influence of drafted Veterans from World War II through the Gulf War, as Fathers and Grandfathers directly served in all of them. Before PTSD it was called “shell shock”, so the phenomenon and influence on children growing up in that era is hardly new.

              In reality, ALL influence matters when talking about a thirteen-year old child taking a human life. But I kinda doubt it w

              • Re:draft, Vietnam (Score:5, Informative)

                by _merlin ( 160982 ) on Sunday February 22, 2026 @03:46AM (#66003662) Homepage Journal

                In reality, ALL influence matters when talking about a thirteen-year old child taking a human life. But I kinda doubt it was the potential vegan inside that drove that.

                The victim was 13. The perpetrator is 64 now, so he was 20 or 21 at the time. This was an adult who had sex with and murdered a 13-year-old child. Why do you keep repeating that the murderer was 13 when even the summary gives you enough information to know this isn't true?

                • In reality, ALL influence matters when talking about a thirteen-year old child taking a human life. But I kinda doubt it was the potential vegan inside that drove that.

                  The victim was 13. The perpetrator is 64 now, so he was 20 or 21 at the time. This was an adult who had sex with and murdered a 13-year-old child. Why do you keep repeating that the murderer was 13 when even the summary gives you enough information to know this isn't true?

                  I stand corrected. And stand by my original statement. There’s nothing normal or regular about that behavior at any age. We don’t often hear of people snapping in the rather unique way to include peodophilia, rape, and murder. That takes a broken mind.

          • Keep reaching for those straws. Eventually you'll blame micro plastics and social media for that murder 44 years ago.

      • by Tablizer ( 95088 )

        > We donâ(TM)t need war-driven PTSD to make citizens snap today. We have SSRIs now.

        There is no evidence SSRI's increase violence if prescribed right.

        • > We donâ(TM)t need war-driven PTSD to make citizens snap today. We have SSRIs now.

          There is no evidence SSRI's increase violence if prescribed right.

          That last part of your statement was written by a lawyer standing in a pool of mass shooter blood pretending it’s whine.

          Just remember that as a society ignorantly continues to blame the inanimate gun and not the drugged human pulling the trigger.

          • Re: (Score:1, Troll)

            by gweihir ( 88907 )

            Guns are force amplifiers and require very little skill to use and almost no preparation. So, say, 5% of the dead are on the shooter, but the other 95% are on those that made gun access too easy.

            Have a look some times at how it goes when somebody tries to do a mass-killing with a knife. Typically does not go so well for them.

            • Re: (Score:3, Insightful)

              by geekmux ( 1040042 )

              Guns are force amplifiers and require very little skill to use and almost no preparation. So, say, 5% of the dead are on the shooter, but the other 95% are on those that made gun access too easy.

              400 million guns are in circulation in America right now. And sadly with ALL that “easy” access, do you know what the overwhelming majority of gun deaths in America are attributed to?

              Suicide. Also known as one of those magical words you can’t say on YouTube or accurately state when talking about gun “violence”.

              And we wonder why ignorant people want to pin all the harm on the inanimate object? Do we go around blaming full-auto-you-can-eat buffets and high-capacity soda cups

              • I believe your data and draw a different conclusion. Suicide is the biggest fraction of US gun deaths.

                "Protecting your family" means not providing access to a gun. A gun is the most effective way to turn a transient suicidal impulse into an untreatable, fatal injury.

                Yes, there are many ways to die and it is hard to stop someone truly determined, but few have so little time for remorse or rescue between impulse, action, and death.

          • Blaming the human or blaming the gun are two extremes that miss the actual point. Mass shootings are not perpetrated by guns alone. They are also not perpetrated by humans alone. There are perpetrated by humans with guns. So the logical solution is to reduce the amount of humans with guns. It's ok to have guns, just make sure they don't end up in the hands of humans too easily or too often.

          • by Tablizer ( 95088 )

            Ya right, "everything's rigged, subject matter experts are all out to eat your pets". Zzzzzzz

  • Panopticon mass surveillance is "justified" and the police are "good". Therefore, all should "eagerly submit" to 23andMe, Flock, Palantir, ICE, and NSA PRISM. "If you have nothing to hide, you have nothing to fear." "Trust us."
  • We jail punish people to
    1. deter others,
    2. to protect society from criminals
    3. to reform criminals

    I very much doubt jailing this man will do any of these three things. In the mean time we have given up our privacy and allowed the government yet another powerful way to track us.
    So, other than revenge, can anyone say society is better off because of this new power to solve old crimes?
    • I think that you're incorrect, that this WILL deter others, by giving the impression that we will catch them eventually if they commit murder.

      There's also the idea that the criminal justice system in general pursuing crimes even if it takes a long time for the most serious ones, helps prevent people attempting vigilante justice.

      • Cool. Please give us some examples of specific situations youâ(TM)ve been in when you were going to murder another person, where (at least in the moment) you felt that it was the right and justified thing to do, and the ONLY thing that made you put the knife down was your fear of punishment. Not moral or social qualms, just your own cowardice.

          â¦what's that? You're not that sort of person? But you so confidently predict the behavior of those who are!

        • You’ve shifted my point into something I never argued.

          Deterrence doesn’t require me personally to have almost committed murder. It’s a populationlevel effect observed across criminology: when the state reliably investigates and solves serious crimes, the expected cost of committing those crimes rises, and some fraction of wouldbe offenders change their behavior. That’s true even if neither you nor I were ever in that category.

          You’re also treating “people who commit murder

      • by dgatwood ( 11270 )

        I think that you're incorrect, that this WILL deter others, by giving the impression that we will catch them eventually if they commit murder.

        Realistically, probably not. The kind of person who would rape and murder a 13-year-old girl almost certainly isn't thinking about whether he'll get caught.

        And more broadly, there's no evidence that the death penalty makes murder less common, so if that's not enough to move the needle, then inadequate fear of getting caught likely doesn't play much of a role in crime rates.

        There's also the idea that the criminal justice system in general pursuing crimes even if it takes a long time for the most serious ones, helps prevent people attempting vigilante justice.

        This is very true.

        • It doesn't have to be perfect to still have an effect. Though yes, I'd argue that our current system is already good enough that for like 99% of the murders remaining, serious thought on the consequences did not occur. They thought they'd never be caught or even just didn't care in the heat of the moment.

          Also, getting as specific as this crime isn't as necessary. If it deters somebody from murdering their fully adult spouse or even their drug dealer, good enough.

    • I may be cynical, but I think most people want people jailed just for revenge or in some cases jealousy.

      I think this person should be jailed because it will provide some healing and restoration to the family. Anything to block generational trauma that could result in other bad incidents is worth it. Plus, there's also the societal protection factor. However minor the chance of a senior committing murder is, it does happen.

  • I get that they may not have had such ready access to the tech in 1982, but did they have to wait this long, surely the tech was available by the 2000s or the 2010s.
  • by Tom ( 822 ) on Sunday February 22, 2026 @03:28AM (#66003656) Homepage Journal

    The FBI, with its access to familial genealogical databases

    Wait, what?

    Why?

    I'm beginning to understand why Americans are worried about drifting into a police state.

  • Can I start by saying that I am completely opposed to the mass collection of DNA from those who have not been convicted of a crime.

    However, in cases like this where DNA evidence has produced a very short list of suspects for a very serious crime, I can't help wondering if it should really be necessary to lurk around trying to collect discarded cigarettes.

    Surely a mechanism could be invented allowing a judge to permit the police to collect DNA from a small number of suspects on the understanding that no DN

    • No advantage. If you can convince a judge to follow such a privacy invading procedure, you can already obtain a home search and collect a trash can or dirty panties. The point of the cigarette butt is you can do it without the perpetrator understanding they've been cornered, and without violating essential rights of the innocents.

      When comparing the advantage your comment paints (a real time saver for the police) to the drawbacks (literally mouth-raping innocents), it does not seem to me, to be a sensible ba

  • This is not what I want.
    This is what's going to be said and that will happen.
  • IIRC (it was a long time ago).
    Possibly the first peer to die. I think still the only homicide. A couple suicides and several car accidents.

Memory fault -- brain fried

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