Tres Mal Errors with DNA Evidence

A story in the Denver Post begins with the disturbing news that

A malfunction in a DNA processing machine led to the scrambling of samples from 11 Denver police burglary cases, officials acknowledged Friday. It took more than two years for the department to discover the errors. As a result of the mix-up, prosecutors are dismissing burglary cases against four people, three of whom had already pleaded guilty.

(Continued on the FSSL blog … )

Get Serious: The US Department of Justice’s Amicus Brief in Haskell v. Harris

As the U.S. Court of Appeals for the Ninth Circuit returns to the question of the constitutionality of California’s DNA database law, the United States has weighed in with an amicus brief. It is worried (or should be) that the en banc panel will take too seriously the Supreme Court’s references to “serious offenses” in Maryland v. King, the DNA-on-arrest case decided last June. The Maryland law that the Supreme Court narrowly upheld authorizes DNA collection for violent felonies, burglaries, and attempts to commit those crimes. The California law under attack in Haskell is broader, applying to all felony arrests including those that would seem rather petty to the casual observer. (The federal law is broader still, encompassing every offense, no matter how trivial, for which a person is dragged into custody.)

Consequently, it comes as no surprise that the federal government wants the Ninth Circuit to read King expansively, whereas the ACLU, which represents the plaintiffs in Haskell, is pressing for the narrowest possible reading. … [read more on FSSL]

Maryland v. King: The Dissent’s Ten Second Rule

The four dissenting Justices in Maryland v. King insisted that DNA databases and fingerprint databases are as different as night and day. As NYU Law Professor Erin Murphy put it:

Most powerfully, Justice Scalia explained (partially through the use of a chart) why fingerprinting differed dramatically from DNA typing. He observed that known fingerprints are not “systematically compared” with latent prints from unsolved crime scenes (in contrast to DNA), and even if so, courts have never approved such action. He also observed that while fingerprinting may not even be a “search,” analysis of genetic code certainly is.

(Murphy 2013, p. 166, note omitted). Relying solely on Justice Scalia’s “powerful” assurances, she adds that

Police have never routinely collected or used photographs or prints for random crime-solving purposes; both were always mainly for identification of persons already suspected of a crime (i.e., individualized suspicion).114 We know this intuitively: how common are newspaper headlines about thirty-year-old cases solved through “cold hit” fingerprint or mug shot matches, or exonerations based on a hit to a fingerprint or photograph newly uploaded to the database?

114. See King, 133 S. Ct. at 1987-88 (Scalia, J., dissenting). Indeed, police could not have used photos or fingerprints for random crime-solving even if they had wanted to, since it was not until twenty or so years ago–when large biometric databases were developed–that it was even possible to conduct a random automated comparison between known files and crime scene samples.

Id. at 177-78. There are several problems with Justice Scalia’s claims as well as this gloss on them. … [read more]

Maryland v. King: When Being Smart and Witty Isn’t Enough

Justice Scalia’s dissenting opinion in Maryland v. King, the arrestee-DNA case, has been praised as “one of the best Fourth Amendments dissents, ever” and his “smartest, wittiest ruling of all time” (Rosen 2013). But one man’s wit is another’s vitriol, and according to another law professor, the opinion is “dripping with contempt” (Feldman 2013). Stylistically, this opinion is more evidence that the art of writing with courtesy as well as conviction has been lost. Substantively, what makes this dissent “one of the best”–other than one’s feelings about which result is correct? It cannot be that the opinion sets forth some enduring principle for understanding and applying the Fourth Amendment…. [read more]

Ninth Circuit Upholds Indefinite Retention of DNA Samples: But Why Retain Them?

How strong are the justifications for retaining DNA samples after the identifying profiles are entered into a law enforcement database? According to the majority of the Ninth Circuit panel in Kriesel III, the “primary justification” is that “match confirmation” ensures “the continued accuracy and integrity of the CODIS system.” That is … [continued on the FSSL blog].

The Population-wide DNA Database

The August ABA Journal landed in my mailbox. Usually, I ask reporters to check the wording with me before quoting me, but I neglected to do so some weeks ago, when Mark Walsh asked me about DNA databases in the aftermath of the Supreme Court’s opinion in Maryland v. King. Mr. Walsh’s article quotes me as follows: “Is the point of arrest the sensible place to draw the line? I can imagine a system in which you take a sample from everyone. Newborns already have a heel prick taken for certain genetic testing. At the same time you could take a DNA sample. Not that you expect a newborn to commit a crime, but 20 years later the sample is there in the database.”

Oops! I said that? I meant to say this: “Is the point of arrest the sensible place to draw the line? I can imagine a system in which you take a sample from everyone. Newborns already have a heel prick taken for certain genetic testing. Along with the genetic tests of the DNA, you could obtain a DNA profile. Not that you expect a newborn to commit a crime, but 20 years later the profile is there in the database.” The critical difference: “profile,” not “sample.”

For more on creating a population-wide database with police never touching your DNA, see this FSSL blog posting.

Good Point, Bad Math: DNA Database Statistics Misunderstood (Again)

An op-ed article in yesterday’s New York Times speaks of DNA database hits as “high risk.” That police, prosecutors, defense lawyers, and juries should not accept every hit as conclusive proof of guilt is quite true. To prove the point, the article calls attention to a false arrest in the ongoing California case of the murder of millionaire investor Raveesh Kumra — a matter that made the news last month. Although the facts of the case are atypical, it is a warning to overly credulous police and prosecutors.

The article, by Hastings Law Professor Osagie K. Obasogie, also rehashes two dated — and previously refuted (or so I think) incidents — that are supposed to show that DNA databases are producing lots of false hits. Some of the factual and statistical errors in the article are identified in the Forensic Science, Statistics, and the Law Blog (

Ninth Circuit Upholds Indefinite Retention of DNA Samples: Kriesel III

Thomas Kriesel wants his blood back. The federal government forced him to give a sample for the FBI’s national DNA databank while he was on probation following his imprisonment for conspiring to possess methamphetamine with the intent to distribute it. After completing his sentence, Kriesel sued the government. He demanded that it remove his identifying profile from the federal database and return his blood sample.

The district court held that he was not entitled to expungement of the profile. On appeal, he dropped that part of his claim, but continued to argue for the return of the blood sample. Over a clamorous dissent, the Ninth Circuit upheld the indefinite retention of the sample. Comments on the opinions are on the FSSL blog.

Activity vs. Source Level Propositions: It Looks like Raffaele Sollecito’s DNA Was on the Bra Clasp, But How Did It Get There?

The title of a New Scientist news report — “Software Says Amanda Knox’s DNA Wasn’t at Crime Scene” — suggests that a new study has excluded Knox as a killer of Meredith Kercher. Not so fast, says the Professor David Balding, the author of the study.

Balding, a statistical geneticist at University College London, has made important contributions to the statistical evaluation of forensic DNA profiles. Now he is developing an open-source program to make inferences about the contributors to low-template DNA samples — samples that have too few copies of DNA fragments to amplify reliably.

An article in the Proceedings of the National Academy of Sciences (USA) describes the program and applies it to an electropherogram the police obtained from one sample in the Knox-Sollecito case. Seeking to clarify the New Scientist report, Balding describes this finding on his website … [continued on FSSL]