The Court’s opinion, penned by Justice Kennedy, enumerated the arguable benefits of routine DNA collection before conviction, concluding with with the observation that “[f]inally, in the interests of justice, the identification of an arrestee as the perpetrator of some heinous crime may have the salutary effect of freeing a person wrongfully imprisoned for the same offense.” To support this conclusion, Justice Kennedy added a quotation from the important and gripping book Actual Innocence: Five Days to Execution and Other Dispatches from the Wrongly Convicted . As quoted in the justice's opinion, the authors of Actual Innocence -- Barry Scheck, Peter Neufeld, and Jim Dwyer -- had written that “[P]rompt [DNA] testing . . . would speed up apprehension of criminals before they commit additional crimes, and prevent the grotesque detention of . . . innocent people.”
I. Toward More Punctility
Mr. Liptak noted that this quotation was not “especially punctilious.” One might think that the problem is that the quotation speaks to preventing erroneous convictions, whereas the sentence it is supposed to support is about "freeing a person wrongfully imprisoned." (Emphasis added.) But Mr. Liptak's point, which turns out to be related, was that “[t]hose first three dots covered a lot of ground. They took the place of more than six sentences and suggested a different point than the one the authors were making.”
What exactly was that little ellipsis hiding? To be particularly punctilious, let’s look at the preceding paragraph, all the omitted words, and a few that follow. This material reads as follows (with the quoted part highlighted):
All wrongfully convicted people take the lash of punishment for someone else's crime; that is the very definition of their predicament. Far too often, they are surrogates for serial criminals and killers, as in California, where Kevin Green carried the weight for a crime by Gerald Parker, who for twenty years stood unprosecuted for five murders. In Oklahoma, Robert Miller was condemned to die for murdering and raping two elderly women before DNA testing put a man named Ronnie Lott in their houses, as well as in the homes of several other women who survived his rapes. In Chicago, Rolando Cruz and Alejandro Hernandez were sentenced to death for killing Jeanine Nicarico, although it turned out that Brian Dugan admitted to murdering Jeanine and five others, including children, during sexual assaults. In North Carolina, Ronald Cotton was cleared of two rapes committed by a man tied to eight others. In Virginia, David Vasquez, a borderline mentally retarded man, pleaded guilty to raping a woman and hanging her from a pipe. Vasquez said he was innocent but copped a plea to avoid the death penalty. The time he served belonged to Timothy Spencer, who raped and murdered not only the victim in the Vasquez case, but three other women, all of them hanged. And because Spencer ultimately was sent to death row for the murders, he was not prosecuted for eight other rapes in which he was the prime suspect.The second paragraph on "prompt testing" is a little confusing. How will "prompt testing" of rape kits "prevent the lengthy detention of innocent suspects and immediately put the police back to the task of finding the real perpetrator" when there is no match to a convicted offender in the database? Sticking to cold hits, there will be more of them if arrestee DNA profiles are placed in the database along with the profiles of convicted offenders and are periodically searched against the database of profiles from unsolved crimes. Statements from the matching individuals might exonerate some convicted offenders (for whom post-conviction DNA testing has been unavailable or ambiguous under the circumstances of the cases). Furthermore, these cold hits might prevent the arrests and subsequent convictions of some innocent suspects (who do not receive prompt DNA testing or whose exclusion as the source of the crime-scene DNA is not sufficient, under the circumstances of the case, to demonstrate their innocence).
Each year, the technology for linking and solving these kinds of crimes gets faster and cheaper. Computers can sort through data banks of DNA samples with dazzling speed and connect identical profiles among far-flung atrocities. If a genetic profile of a criminal is already lodged in a data bank, identifying him is a no-brainer. Even if a pattern of crimes can't be tagged to a known criminal, prompt testing will prevent the lengthy detention of innocent suspects and immediately put the police back to the task of finding the real perpetrator. The failure to take full advantage of this technology, both for solving crimes and freeing the innocent, is a national scandal. Current investigative approaches must change.
Typically, DNA testing of evidence is done only after a suspect has been apprehended—and then takes two or three months. Hundreds of thousands of rape kits from unsolved cases are thrown out or sit in dead storage for years with no effort made by the authorities to run DNA tests, squandering opportunities to identify serial offenders and clear the wrongly convicted, such as Kevin Green. If crime scene materials were tested and catalogued immediately, one case could be linked quickly to others. Since a forensic DNA test can be completed in two or three days, crime laboratories could be given the resources to finish a case within a week. This would speed up apprehension of criminals before they commit additional crimes, and prevent the grotesque detention of thousands of innocent people.
And that goes not only for rapes and homicides but for burglaries, robberies, assaults—any kind of incident in which a criminal may have left a trace of skin, saliva, hair, or any biological evidence.
The next paragraph, however, makes it clear that the "prompt testing" demanded by the the authors of Actual Innocence is only the prompt testing of crime-scene and victim samples. They take no position (at least not here) on the value of "prompt testing" of arrestees, and one of them, Peter Neufeld, told Mr. Liptak that all three "never endorsed arrestee databases.” 
Given that Actual Innocence did not explicitly endorse arrestee sampling, how should the opinion have used some of the book's prose? How about a parenthetical phrase -- the darling of the ever punctilious Bluebook (the legal style manual so dear to student law review editors). The paragraph should have read:
Finally, in the interests of justice, the identification of an arrestee as the perpetrator of some heinous crime may have the salutary effect of freeing a person wrongfully imprisoned for the same offense. "[P]rompt [DNA] testing . . . would speed up apprehension of criminals before they commit additional crimes, and prevent the grotesque detention of . . . innocent people." J. Dwyer, P. Neufeld, & B. Scheck, Actual Innocence 245 (2000) (referring to the importance of prompt testing of crime-scene samples).
II. Arrestee DNA and Resolving Unsolved Cases
So I have to agree with Mr. Liptak. The citation lacks (parenthetical) punctility. But is it not at least consistent with the logic of the paragraphs from which it quotes? To achieve maximum exonerations and to avoid apprehension of the wrong people for unsolved crimes, should not DNA profiles from arrestees go into the databases for subsequent searches against crime-scene samples along with those of convicted offenders?
Well, not necessarily. It could be argued that arrestees are just gravy -- that if there is not enough money to fund lavishly three sources of samples, crime-scene samples and convicted-offender samples should come first. Interestingly, a brief of "14 Scholars of Forensic Evidence" (that is, law professors) filed on behalf of Mr. King claimed that arrestee sampling exacerbates backlogs and is not necessary to exonerate the innocent. Should a court therefore hold a DNA database law unconstitutional on the ground that a state should be spending more money on one part of the system than another? What if the state then turns around and spends more money on the parts the court, guided by this scholarship, thought more important? Should the court function as a kind of equitable master periodically reviewing funding decisions, average processing times for crime-scene samples, and the number and training of the investigators collecting DNA from crime-scenes? These things, among others, bear on how well the system works in identifying true offenders, but do they have the necessary clarity and susceptibility to judicial supervision to be dividing lines of constitutional magnitude?
I doubt it. As long the legislature pursues a reasonable combination of the essentials required of a database for investigating offenses in which DNA evidence can be recovered, courts should not vitiate the legislative judgment on the ground that the system could be realigned to be still more effective. Courts faithfully interpret the mandate of the Fourth Amendment when they uphold measures that are not unreasonably invasive of personal security. That these measures could be made more efficacious is important in formulating and implementing public policy, but it cannot be the basis for a ruling of unconstitutionality.
III. Dr. Mengele Comes to the Databanks
The Court's reliance on Actual Innocence prompts a final thought (for now). Immediately after the paragraphs that I quoted in full, the authors add that
No matter whose privacy is at stake, data banks full of genetic information can be dangerous, particularly when the samples disproportionately come from black and brown men. Modern-day Mengeles, in search of evidence for master-race theories, would find data bases irresistible in the quest for a genetic link to criminality. A simple reform could slam the door on such eugenic inquiries. Any leftover blood, tissue, or DNA should be discarded once a profile has been stored.This passage is not a model of clarity. I do not say this because I disagree with the conclusion. On the contrary, I have written that the case for indefinite sample retention is weak.  My concern is with the poorly woven strands of the argument.
Let us remember who Josef Mengele was and what he did. As an SS physician, assigned to the Auschwitz concentration camp, "with full license to maim or kill his subjects, Mengele performed a broad range of agonizing and often lethal experiments with Jewish and Roma ('Gypsy') twins, most of them children. ... Mengele firmly endorsed the doctrine of National Socialist racial theory and engaged in a wide spectrum of experiments which aimed to illustrate the lack of resistance among Jews or Roma to various diseases. He also attempted to demonstrate the 'degeneration' of Jewish and 'Gypsy' blood through the documentation of physical oddities and the collection and harvesting of tissue samples and body parts. Many of his 'test subjects' died as a result of the experimentation or were murdered in order to facilitate post-mortem examination." 
What would Mengele do with the DNA samples in a law enforcement repository (were he given access to one, in violation of the laws governing many of them)? Look for some association between the genes of all the individuals in the database and a comparison group of presumably law-abiding individuals? Suppose, contrary to previous research, he found some plausible relationship between a genotype and criminality. Might he then discover that this genotype exists in a larger proportion of the "black and brown men" convicted of crimes than in the men of his favored "master race"? How does the disproportionate representation of the former groups in the criminal databanks make this outcome more likely -- if that is what "particularly dangerous" refers to?
This is not to deny that genetic arguments for racism -- no matter how contrived -- will appeal to some people. There are, by way of comparison, Holocaust deniers and plenty of people willing to dismiss evolution as merely "a theory." But the people who would believe the resurrected Mengele of Actual Innocence hardly need more pseudo-science to convince them that "black and brown men" are genetically inferior. That DNA samples should be destroyed because a Mengele could use them to demonstrate the racial inferiority of some groups seems like one of weakest arguments for sample destruction.
In any event, there is a real connection between Mengele and DNA evidence. Mengele eluded capture for 34 years, from 1945 until his death in 1979. He was buried as "Wolfgang Gerhard" near Sao Pãolo. In 1985, the corpse was exhumed and the remains identified as Mengele. In 1992, DNA evidence confirmed this conclusion. 
1. Adam Liptak, Cited by a Justice, But Feeling Less Than Honored, N.Y. Times, June 11, 2013, at A15.
2. Barry Scheck, Peter Neufeld, & Jim Dwyer, Actual Innocence: Five Days to Execution, and Other Dispatches From the Wrongly Convicted (2000).
3. David H. Kaye, Behavioral Genetics Research and Criminal DNA Databanks, 69 Law & Contemp. Probs. 259 (2006).
4. United States Holocaust Memorial Museum, Holocaust Encyclopedia: Josef Mengele http://www.ushmm.org/wlc/en/?ModuleId=10005143. Accessed June 13, 2013.