Bad Math or Passable Law? DNA Testing in the Continuing Prosecution of Amanda Knox and Raffaele Sollecito

In an April posting, I raised some questions about an op-ed ("Justice Flunks Math") on the judge's refusal to depart from the court-appointed expert's written report in the prosecution of Amanda Knox and Raffaele Sollecito. This week, a flurry of opinionated comments appeared, and I let those that seemed to have at least some analysis or substance through the gate.

In my previous posting, I took issue with the op-ed's assertion that the trial judge "demonstrated a clear mathematical fallacy: assuming that repeating the test could tell us nothing about the reliability of the original results" and its apparent suggestion that retesting the same DNA sample would be comparable to testing a coin for bias by repeatedly tossing it. I argued that "[w]ithout some specification of precisely what made the initial testing problematic and whether those problems could be reduced sufficiently with retesting, it seems precipitous to convict the judge who overturned the guilty verdict of 'bad math.'"

Whatever the merits of the indictment of the judge, my thanks to those who offered information on whether retesting might be significantly more revealing than the initial testing. That is an interesting question in its own right.

In this regard, an author of the op-ed, Professor Leila Schneps kindly explained that the "confirming retest" (the phrase in her op-ed) did not mean a retest of the same sample (like flipping a coin again) but rather an analysis of a "new knife blade sample," a "rich sample ... from the place where the blade joins the handle of the knife." This new sample, she suggests, might be "positive for Meredith Kercher," in which case, "it would have correctly settled two of the questions left outstanding in the courtroom: was the first electropherogram showing the DNA on the knife correctly interpreted as Meredith's, and was Meredith's DNA actually on the knife?"

If we posit that the new sample is large enough to produce unambiguous results, then it could reveal whether "Meridith's DNA [was] actually on the knife." But Professor Schneps also states that the "rich sample" was "significantly lower than the quantity 'advised' by the kit, although the kit's website shows many examples of tests on smaller samples, some even smaller than the knife blade DNA, that gave positive and accurate results."

If the sample is this impoverished, are we not back in the realm of low-template DNA testing, where the worry is that stochastic effects can be dominant? The mathematical argument here seems to be that even though it might not be surprising to spot, by chance alone, some peaks in a new test that also are present in Meridith's genotype, the probability of those peaks plus the ones seen in the original testing of a different sample from the knife would be negligible unless Meridith's DNA was on the knife. In this way, the additional testing overcomes the low signal-to-noise ratio in each sample. That is a fair argument (as far as it goes), and the same logic underlies some protocols for testing contact DNA.

Still, given the difficulties and the level of discord over the best approaches to conducting and interpreting LT-DNA testing (see, e.g., A. Carracedo, P.M. Schneider, J. Butler & M. Prinz, Focus issue—Analysis and Biostatistical Interpretation of Complex and Low Template DNA Samples, Forensic Science International: Genetics 6 (2012) 677–678), and the court's experts' concerns about contamination, I wonder whether even the most mathematically erudite judge would have been so quick to order additional DNA testing in this case. Consequently, I am not yet prepared to give the judge a flunking grade for "a clear mathematical fallacy."

Potshots: “Blank Stares” and “No Data” on Latent Fingerprint Identification

According to as astute an observer as David Faigman,

In ... fields such as latent fingerprint identification, firearms, clinical psychology, and clinical psychiatry ... , if judges ask the question, “Where are the data?” they would be met with blank stares. If you ask a latent fingerprint examiner, “Where are your data?” the answer is likely to be, “Data. We have no data. In fact, we don't need data. We're specialists.” ... Many of these experts have been practicing their trade for twenty-five years; they know it when they see it. ... Under Daubert, however, even if your data happen to be experience, you have to be able to articulate how you came to know what you think you know. (Faigman 2013, 914).

A footnote explains that being “able to articulate how you came to know what you think you know” can be accomplished by “checking the basis for believing that the experience will produce reliable testimony.” (Ibid., 914 n. 64).

Now, I am no fan of claims of fingerprint examiners to be able to match latent prints to reference prints with absolute certainty (NIST 2012) and of lax and superficial court opinions allowing such testimony. (Kaye 2013; Kaye, Bernstein and Mnookin 2011). But the assertion that there are absolutely no data to show that latent print examiners can “produce reliable testimony” is too much even for me to swallow. Indeed, in his treatise on scientific evidence, Professor Faigman does not insist that “no data” exist. The treatise correctly recognizes that “[a] few well-designed studies have now been conducted” (Faigman et al. 2012, § 33:56). To the list of six studies noted in the treatise (ibid., § 33.49 n. 10), one can add Tangen, Thompson, and McCarthy (2011). (As explained here last June, this Australian study showed a false negative rate of under 8% and a false positive rate of under 1% (Fingerprinting Error Rates Down Under, June 24, 2012)).

Perhaps Professor Faigman meant to say that even if data exist to support the judgments of fingerprint analysts—as they clearly do at a general level—a particular examiner’s judgments are not based on data, but on standardless, subjective impressions of the degree of similarity that warrants an identification or an exclusion. They just “know it when they see it.” That observation is closer to the mark (no pun intended). It is the gist of David Harris's contention that "most forensic science does not qualify as science in any true sense of that term." (Harris 2012, 36). Like Professor Faigman, Professor Harris complains that "[d]isciplines like fingerprint analysis, firearms tool-mark analysis, and bite-mark analysis have no basis in statistics, and do not originate in inquiry conducted according to scientific principles. Rather, they rely on human judgment grounded in experience ... without reference to rigorous and agreed-upon standards." (Ibid.) Identification experts who do not follow a protocol with quantitative or other external standards to achieve high inter-rater reliability should not insist that they are following the "scientific method." (Compare Kaye 2012, 123).

But "science" is not the only source of useful information, and experiments can measure the levels of accuracy for subjective as well as objective procedures. DNA laboratories have verified that DNA analysis performed in a specified way correctly distinguishes between samples taken from the same source and samples taken from different sources.  Indeed, this is the only sense in which it could be said that “DNA profiling [always] ... had known error rates” (Faigman 2013, 913). Even today, the error rates of DNA laboratories in actual case work is not really known. In the same manner, tests of fingerprint analyses performed by trained examiners show that they are capable of routinely distinguishing between marks taken from the same source and marks taken from different sources (with some errors). Again, however, we do not know the error rates of these examiners in actual case work. (Kaye 2012).

Consequently, appropriately documented latent print comparisons undertaken without unnecessary exposure to biasing information, presented with a recognition of the uncertainty in the largely subjective procedure and verified by an independent examiner blinded to the initial outcome as well as the output of an automated scoring system, should survive the “more rigorous test” (Faigman 2013) established in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), and embellished in later cases. Although there is ample room to improve fingerprint comparisons by human examiners and to implement automated systems for latent print work, “blank stares” and “no data” are no longer the only answers available to an objection under Daubert.

References

Faigman, David L. 2013. “The Daubert Revolution and the Birth of Modernity: Managing Scientific Evidence in the Age of Science.” University of California at Davis Law Review 46:893–930.

Harris, David A. 2012. Failed Evidence: Why Law Enforcement Resists Science. New York and London: New York University Press.

Kaye, David H. 2013. “Experimental and Scientific Evidence: Criminalistics.” In McCormick on Evidence, edited by Kenneth Broun, § 207. Eagan, MN: West Publishing Co.

Kaye, David H., ed. 2012. Expert Working Group on Human Factors in Latent Print Analysis, Latent Print Examination and Human Factors: Improving the Practice Through a Systems Approach. Gaithersburg: National Institute of Standards and Technology.

Kaye, David H., David E. Bernstein, and Jennifer L. Mnookin, 2011. The New Wigmore: A Treatise on Evidence: Expert Evidence. New York: Aspen Publishing Company, 2d ed.

Tangen, Jason M., Matthew B. Thompson, and Duncan J. McCarthy 2011. “Identifying Fingerprint Expertise.” Psychological Science 22:995 (available online).

The Constitutionality of DNA Collection Before Conviction: An Updated Scorecard

Note: This posting updates previous ones. It is current as of March 30, 2013.

Fifteen years ago, Louisiana adopted a law mandating that "[a] person who is arrested for a felony sex offense or other specified offense . . . shall have a DNA sample drawn or taken at the same time he is fingerprinted pursuant to the booking procedure." As of mid-2012, 28 states and the federal government had laws providing for DNA sampling before any conviction is obtained. Most other countries with DNA databases also collect samples on arrest.

The DNA-before-conviction (DNA-BC) laws in the U.S. had a placid childhood, with surprisingly few challenges to their constitutionality. This period of calm is over. In contrast to their older brother, laws mandating DNA collection after conviction (DNA-AC), which have been upheld in scores of cases, DNA-BC laws have provoked conflicting constitutional opinions. The Supreme Court heard argument in Maryland v. King in February 2013 and is likely to rule on the issue in June 2013.

This posting presents a scoreboard on the litigation and scholarly commentary to date. If any players or contests have been omitted, I hope that readers will correct those omissions by leaving a comment. The law review articles listed in the table do not include ones on DNA-AC. Authors who have contended that these databases are unconstitutional would reach the same conclusion for a database that includes arrestees, but the lower courts have resoundingly rejected their analyses. Therefore, little would be gained by keeping track of the many articles on convicted-offender databases.

The tables make the point that there is no clear consensus among lower courts on the constitutionality of taking DNA samples during a custodial arrest (or at another point before conviction) with the intention of running database searches (in the absence of a warrant and probable cause to believe that the search will produce a hit in the database).

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Table 1. Case law
Appellate: State Supreme Courts (1.5-1.5)

• Mario W. v. Kaipio, Commissioner, 281 P.3d 476 (Ariz. 2012) (state arrestee law for juveniles constitutional insofar as it allows sampling as a booking procedure, but pre-conviction analysis of the sample is unconstitutional under a totality-of-the-circumstances standard and an analogy to searching containers)
• King v. State, 42 A.3d 549 (Md. 2012) (state law requiring sampling after arraignment unconstitutional "as applied" under "totality of the circumstances" balancing test), cert. granted sub nom. Maryland v. King, No. 12-207 (U.S. Nov. 9, 2012)
• Anderson v. Commonwealth, 650 S.E.2d 702 (Va. 2007) (state arrestee law upheld under unspecified balancing test and analogy to fingerprinting as a booking procedure)
• Related case: State v. Franklin, 76 So.3d 423 (La. 2011) (no search warrant required to take a DNA sample from a murder defendant for use in the murder investigation because he had to submit a sample "as a routine incident of booking" anyway)

Appellate: State Intermediate Courts (opinions not reviewed by higher courts) (0-2)

• People v. Buza, 129 Cal.Rptr.3d 753 (Cal. Ct. App. 2011) (unconstitutional under balancing tests), rev. granted, 262 P.3d 854 (Cal. 2011)
• In re Welfare of C.T.L., 722 N.W.2d 484 (Minn. Ct. App. 2006) (state arrestee law struck down as per se unreasonable without probable cause and a warrant)

Appellate: Federal Courts (2-0)

• United States v. Mitchell, 652 F.3d 387 (3d Cir. 2011) (en banc) (federal arrestee law upheld under "totality of circumstances" balancing test)
• Haskell v. Harris, 669 F.3d 1049 (9th Cir. 2012) (state arrestee law upheld under "totality of circumstances" balancing test), reh'g en banc granted, 686 F.3d 1121 (9th Cir. 2012)
• United States v. Pool, 621 F.3d 1213 (9th Cir. 2010) (federal arrestee law upheld under "totality of circumstances" balancing test), vacated as moot, 659 F.3d 761 (9th Cir. 2011) (en banc)
• Related case: Friedman v. Boucher, 580 F.3d 847 (9th Cir. 2009) (an arrest does not justify DNA sampling without an applicable statute)

Trial Courts: Federal (not reviewed by higher courts) (4-1)

• United States v. Thomas, No. 10-CR-6172 CJS, 2011 WL 1627321 (W.D.N.Y. Apr. 27, 2011) (federal arrestee law upheld under "special needs" balancing test), dismissed, No. 11-1742 (2d Cir. Sept. 20, 2011), ECF No. 43
• United States v. Demasi, Crim. No. 12–197, 2013 WL 24818 (W.D.Pa. Jan. 2, 2013) (applying Mitchell)
• United States v. Robinette, No. 13–CR–0003 AWI BAM, 2013 WL 211112 (E.D.Cal. Jan. 18, 2013) (refusing to order the government to delay DNA collection at least until the Supreme Court rules in King v. Maryland)
• Amended Order Denying the Government's Motion to Compel DNA Samples, United States v. Frank, No. CR-092075-EFS-1(E.D. Wash. Mar. 10, 2010), available at http://www.dnaresource.com/documents/USvFrank.pdf (applying totality balancing to a limited list of interests to find compulsory collection before conviction unreasonable)
• United States v. Fricosu, No. 10-cr-00509-REB-01 (D. Colo. Feb. 22, 2012) (federal law upheld under totality standard), available at http://www.denverda.org/DNA_Documents/Arrestee_Database/Fricosu.pdf.
• Related case: United States v. Purdy, No. 8:05CR204, 2005 WL 3465721 (D. Neb. 2005) (forcibly taking a buccal swab from an arrestee violates Fourth Amendment in the absence of a statute providing for a uniform and limited system of sampling)

Trial Courts: Federal (reviewed by higher courts) (2-1)

• United States v. Mitchell, 681 F.Supp.2d 597 (W.D.Pa. 2009) (federal law held unenforceable), rev'd, 652 F.3d 387 (3d Cir. 2011) (en banc)
• United States v. Pool, 645 F.Supp.2d 903 (E.D.Cal. 2009) (federal arrestee law upheld under "totality of circumstances" balancing test), aff'd, 621 F.3d 1213 (9th Cir. 2010), affirming opinion vacated as moot, 659 F.3d 761 (9th Cir. 2011) (en banc)
• Haskell v. Brown, 677 F.Supp.2d 1187 (N.D. Cal. 2009) (denying a preliminary injunction against the enforcement of California's arrestee sampling law in large part because the balance of interests establishes that the requirement is reasonable), aff'd sub nom. Haskell v. Harris, 669 F.3d 1049 (9th Cir.), reh'g en banc granted, 686 F.3d 1121 (9th Cir. 2012)

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Table 2. Law Review Articles and Notes
Faculty

• D.H. Kaye, The Constitutionality of DNA Sampling on Arrest, 10 Cornell J.L. & Pub. Pol'y 455-508 (2001) (a statute with sufficient protections to confine the government to identifying information is constitutional under the special needs exception)
• Tracey Maclin, Is Obtaining an Arrestee's DNA a Valid Special Needs Search Under the Fourth Amendment? What Should (and Will) the Supreme Court Do?, 34 J.L. Med. & Ethics 165, 178-82 (2006) (predicting that the Supreme Court will uphold taking DNA from arrestees under a balancing test but stating that it should reject the practice as per se unreasonable)
• D. H. Kaye, Who Needs Special Needs? On the Constitutionality of Collecting DNA and Other Biometric Data from Arrestees, 34 J.L. Med. & Ethics 188 (2006) (proposing a "biometric information exception" to the warrant requirement)
• Brian Gallini, Step Out of the Car: License, Registration, and DNA Please, 62 Ark. L. Rev. 475 (2009) (Arkansas law unconstitutional because it does not require a judicial finding of probable cause arrest, contains inadequate safeguards to protect the samples and records, and because it does not fall within an established exception to the warrant requirement)
• Kevin Lapp & Joy Radice, A Better Balancing: Reconsidering Pre-Conviction DNA Extraction from Federal Arrestees, 90 N. Car. L. Rev. Addendum 157 (2012) (pre-conviction DNA extraction should be permitted only after a neutral third-party finding of probable cause and DNA samples should be destroyed)
• David H. Kaye, Drawing Lines: Unrelated Probable Cause as a Prerequisite to Early DNA Collection, 91 N.C. L. Rev. Addendum 1 (2012) (a formal finding of probable cause for an unrelated arrest is not constitutionally required)
• David H. Kaye, On the "Considered Analysis" of DNA Collection Before Conviction, 60 UCLA L. Rev. Discourse 104 (2013)
• David H. Kaye, A Fourth Amendment Theory for Arrestee DNA and Other Biometric Databases, 15 U. Pa. J. Const. L. No. 4 (forthcoming 2013)
• Related article: Robert Molko, The Perils of Suspicionless DNA Extraction of Arrestees Under California Proposition 69: Liability of the California Prosecutor for Fourth Amendment Violation? The Uncertainty Continues in 2010, 37 W. St. U. L. Rev. 183 (2010) (reaching no conclusions)

Student

• Martha L. Lawson, Note, Personal Does Not Always Equal "Private": The Constitutionality of Requiring DNA Samples from Convicted Felons and Arrestees, 9 Wm. & Mary Bill Rts. J. 645 (2001) (the government's interest in mandatory testing of all those arrested outweighs individuals' privacy interests)
• Reneé A. Germaine, Comment, "You Have the Right to Remain Silent. . . You Have No Right to Your DNA" Louisiana's DNA Detection of Sexual and Violent Offender's Act: An Impermissible Infringement on Fourth Amendment Search and Seizure, 22 J. Marshall J. Computer Info. L. 759 (2004) (unconstitutional under balancing test other than special needs)
• Kimberly A. Polanco, Note, Constitutional Law-The Fourth Amendment Challenge to DNA Sampling of Arrestees Pursuant to the Justice for All Act of 2004: A Proposed Modification to the Traditional Fourth Amendment Test of Reasonableness, 27 U. Ark. Little Rock L. Rev. 483 (2005) (constitutional under a balancing test)
• Robert Berlet, Comment, A Step Too Far: Due Process and DNA Collection in California after Proposition 69, 40 U.C. Davis L. Rev. 1481 (2007) (with certain modifications, arrestee DNA sampling as provided for under California law would be constitutional)
• John D. Biancamano, Note, Arresting DNA: The Evolving Nature of DNA Collection Statutes and Their Fourth Amendment Justifications, 70 Ohio St. L.J. 619 (2009) (unconstitutional under special needs and totality of the circumstances tests)
• Corey Preston, Note, Faulty Foundations: How the False Analogy to Routine Fingerprinting Undermines the Argument for Arrestee DNA Sampling, 19 Wm. & Mary Bill Rts. J. 475 (2010)
• Ashley Eiler, Note, Arrested Development: Reforming the Federal All-Arrestee DNA Collection Statute to Comply with the Fourth Amendment, 79 Geo. Wash. L.Rev. 1201, 1220 (2011)
• Lauren N. Hobson, Note, North Carolina's Arrested Development: Fourth Amendment Problems in the DNA Database Act of 2010, 89 N.C. L. Rev. 1309 (2011) (unconstitutional because no existing exception to the Warrant Clause applies) 
• Related note: Jacqueline K. S. Lew, Note, The Next Step in DNA Databank Expansion? The Constitutionality of DNA Sampling of Former Arrestees, 57 Hastings L.J. 199 (2005) (unconstitutional as applied to "former arrestees")

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References

Julie Samuels, Elizabeth Davies, Dwight Pope et al., Collecting DNA From Arrestees: Implementation Lessons, NIJ J., June 2012, http://www.nij.gov/journals/270/arrestee-dna.htm

15 La . Rev. Stat. § 609(A)(1) ("A person who is arrested for a felony sex offense or other specified offense, including an attempt, conspiracy, criminal solicitation, or accessory after the fact of such offenses on or after September 1, 1999, shall have a DNA sample drawn or taken at the same time he is fingerprinted pursuant to the booking procedure."), derived from Act No. 737, approved July 9, 1997, and amended in 2003 (adding the phrase "including an attempt, conspiracy, criminal solicitation, or accessory after the fact of such offenses")

Are Two Heads Better than One? Mathematics and the Amanda Knox Case

In yesterday’s New York Times, “Leila Schneps, a mathematician and mystery writer, and her daughter Coralie Colmez” wrote an op-ed entitled “Justice Flunks Math.” They gave this failing grade to an Italian judge who declined to order a second DNA test in the notorious murder case against the American student, Amanda Knox and her Italian boyfriend, Raffaele Sollecito.

If only the judge understood probability theory, they suggest, he might have ruled in favor of the prosecution's request for another DNA test. In their words:

Whatever concerns the judge might have had regarding the reliability of DNA tests, he demonstrated a clear mathematical fallacy: assuming that repeating the test could tell us nothing about the reliability of the original results. In fact, doing a test twice and obtaining the same result would tell us something about the likely accuracy of the first result. Getting the same result after a third test would give yet more credence to the original finding.

This claim of a mathematical fallacy in the judge’s reasoning, however, rests on an important assumption — that the test results are statistically independent (at least in substantial part). To illustrate their point, Schneps and Colmez explain:

Imagine, for example, that you toss a coin and it lands on heads 8 or 9 times out of 10. You might suspect that the coin is biased. Now, suppose you then toss it another 10 times and again get 8 or 9 heads. Wouldn’t that add a lot to your conviction that something’s wrong with the coin? It should.

But consider this example instead:

You test the surface of a gold coin and test it to make sure it is gold. The test is 90% certain to indicate gold when the metal is gold, so following the advice of Schneps and Colmez, you repeat the test three times and strike gold each time. When you try to sell the coin, however, a more astute buyer weighs it and finds that it does not have the density of gold. It is, in fact a thickly gold plated, lead coin.

Which example is more apt in the Knox case? A Nature blog explained that "[v]ery small amounts of Knox’s DNA were found on a knife located at the crime scene 46 days after Kercher’s murder," but this is not correct. The knife came from Sollecito's kitchen, and a more informed account in the New York Times states that "the court-appointed experts concluded that ... Ms. Knox's DNA was in fact on the handle" -- hardly a surprise given that she may have used it to cook dinner in her boyfriend's apartment. The only thing that made the knife incriminating was a police laboratory finding of DNA from the victim, Meredith Kercher, on the blade. But there was evidence that the knife could not have produced all the wounds, and the court-appointed experts were skeptical of the finding about the blade as well the police laboratory's analysis of "a bra clasp that belonged to the victim found on the floor at the scene 46 days after her murder" said to show Sollecito’s DNA.

Returning to Nature's account:

Speaking at the request of the defence, two forensic scientists, Stefano Conti and Carla Vecchiotti from Sapienza University in Rome, said police investigators failed to follow international protocols for collecting and handling evidence and conducting tests on small genetic samples known as low-copy-number (LCN) DNA analysis. For example, officers were not wearing protective masks or hair caps at the crime scene. ... In addition, Conti said police often used plastic bags, rather than paper, to wrap evidence, heightening the risk of contamination. ... “There are various circumstances do not adhere to protocols and procedures,” Conti told the court.

Consequently, the independent experts concluded that they could not rule out the possibility that the knife and bra had been contaminated by other sources of Knox’s and Sollecito’s DNA, such as other evidence at the crime lab where forensic testing was taking place.

If these experts’ concern — that the original DNA test was simply detecting traces of Kercher's and Sollecito’s DNA that investigators inadvertently transferred to the knife and bra clasp, respectively — then repeating the tests could well continue to detect that DNA — and prove nothing more than the original tests did. If the bra clasp sample showed a mixture of DNA from the victim and Sollecito (and nothing else), for example, then repeating it over and over would not reinforce the prosecution case in the slightest. It would be no different than retesting the surface of the lead coin with its gold plated contamination. The inability of the DNA evidence to demonstrate a convincing link to the defendants would remain after even an infinity of new tests.

Consequently, it is hard to judge Schneps' and Colmez's suggestion that "[t]he judge’s rejection of the retest — at least based on the notion that a confirming retest could tell us nothing about the likelihood that the DNA was a match — was a serious error, one that scuppered an opportunity to get at the truth of Ms. Kercher’s murder."

The judge’s decision may have been mathematically sound, or it may have been as naive and fallacious as Schneps and Colmez propose. They have a nice theory but it is fair to assume that there were uncontaminated samples for new testing? Without some specification of precisely what made the initial testing problematic and whether those problems could be reduced sufficiently with retesting, it seems precipitous to convict the judge who overturned the guilty verdict of "bad math."

Indeed, Schneps and Colmez seem to believe that the judge ignorantly opposed retesting of the small sample of DNA on the blade despite an improvement in the technology of testing low template DNA. They wrote that

Even though the identification of the DNA sample with Ms. Kercher seemed clear, there was too little genetic material to obtain a fully reliable result — at least back in 2007. By the time Ms. Knox’s appeal was decided in 2011, however, techniques had advanced sufficiently to make a retest of the knife possible, and the prosecution asked the judge to have one done. But he refused.

Yet, the judge clearly was open to new methods. He asked the two university experts to ascertain "whether it is possible, by means of a new technical analysis, to identify the DNA present on items 165b (bra clasp) and 36 (knife)." The Conti-Vecchiotti Report, Assignment. Finding "no evidence of cellular material in the samples analyzed," however, his experts concluded that "no DNA suitable for further laboratory investigations (amplification, electrophoresis) was present either on the swabs [tamponature] (A-B-C-D-E-F-G-H-I) taken from Exhibit 36 (knife) or on those (L-M) taken from Exhibit 165B (hooks of the bra)." Id. Conclusions (1). They based this conclusion on the absence of cellular material and the failure of "quantification of the extracts ... conducted via Real Time PCR [to] reveal the presence of DNA." Id. Conclusions (2).

The prosecution disagreed. It asked for still more testing. But Judge Claudio Pratillo Hellmann had had enough. Rather than prolong the appeal -- and the imprisonment of the defendants -- still longer to await tests that his experts told him would be useless, he and the jurors returned their not-guilty verdict. It remains to be seen why this verdict now has been overturned, but it is hardly obvious that "bad judicial math" is the reason.

References

• Natasha Gilbert, Knox Walks Free Due to Unreliable DNA Analysis, Nature News Blog,Oct. 4, 2011
• Elisabetta Povoledo, Italian Experts Question Evidence in Knox Case, N.Y. Times, June 30, 2011, at A6
• Leila Schneps & Coralie Colmez, Justice Flunks Math, N.Y. Times, March 27, 2013, at A23
• The Conti-Vecchiotti Report (translation), Welcome, July 4, 2011.

Later Postings

• http://for-sci-law-now.blogspot.com/2013/05/bad-math-or-passable-law-dna-testing-in.html

In Press: Confronting Science: Expert Evidence and the Confrontation Clause

The coming volume of the University of Chicago's Supreme Court Review will include an assessment of the Supreme Court's trilogy of opinions on the Confrontation Clause and laboratory reports: Jennifer L. Mnookin and David H. Kaye, Confronting Science: Expert Evidence and the Confrontation Clause, preprint available at http://ssrn.com/abstract=2238269.

Abstract: In Crawford v Washington, the Supreme Court substantially changed its understanding of how the Confrontation Clause applies to hearsay evidence. Since then, the Court has issued three bitterly contested expert-evidence-related Confrontation Clause decisions, and each one has generated at least as many questions as answers. This article analyzes this trilogy of cases, especially the most recent, Williams v Illinois.

In Williams, the Court issued a bewildering array of opinions in which majority support for admitting the opinion of a DNA analyst about tests that she did not perform was awkwardly knitted together out of several incompatible doctrinal bases. The most prominent and fully developed argument for admission was that the references to the work of the analysts who actually did the testing but who never testified were admitted for a purpose other than their truth. Although we maintain that this argument is, on the facts of Williams, implausible, we also recognize that in other, relatively limited instances, expert basis evidence might legitimately be introduced for a purpose other than its truth.

After striving for precision on this doctrinal point, we step back and suggest that the ongoing anxiety about how to think about expert evidence and the Confrontation Clause exists in large part because the Court has yet to face directly a set of larger, background concerns. There is significant uncertainty about how, and to what extent, scientific evidence should be treated as special or distinct from other kinds of evidence for confrontation purposes. We suggest that scientific and expert evidence might warrant some limited special treatment, based on what we see as one of the most critical dimensions of scientific knowledge production—that it is a collective, rather than an individual enterprise. Recognizing that scientists inevitably rely and build on facts, data, opinions, and test results of others, we suggest that courts should engage in a modest form of scientific exceptionalism within Confrontation Clause jurisprudence, through efforts to create procedures that respect the fundamental values of the Confrontation Clause, but also adapt when necessary, to the epistemic structures and processes of science.

In Press: The Database and the Dictionary

An improved (I hope!) version of an earlier post on the Ohio Supreme Court's opinion in State v. Emerson will be published in Jurimetrics: The Journal of Law, Science, and Technology (53:4). The current draft is available at http://ssrn.com/abstract=2238400.

Abstract: In State v. Emerson, 981 N.E.2d 787 (Ohio 2012), the Ohio Supreme Court discerned neither a statutory nor a constitutional barrier to retaining an acquitted defendant’s DNA profile in the state’s database when the profile was obtained with a search warrant and the defendant did not request expungement of the database record. The court wrote that the profile fell with the statutory category of “records from forensic casework or from crime scenes” and that “a person does not have standing to object to the retention of his or her DNA profile or to the profile's use in a subsequent criminal investigation.” This essay disputes both these conclusions. It argues that placing or retaining the profile of an acquitted individual, even one obtained with a warrant, in a database for convicted offenders violates the statute and that the affected individual has standing to complain. It concludes, however, that the entry and use of the profile in the database, although not statutorily authorized, does not contravene the Fourth Amendment.

Disgusting DNA

The Whooper Stopper

When my son worked at a pizza restaurant a long time ago, he told me that some of the kids preparing the food would spit into into their handiwork. I tried not to think about it, but the practice, at a Burger King in Vancouver, Washington, has prompted a major decision on the tort of intentional infliction of emotional distress.

The employee with the loose lips probably did not expect the Whopper with cheese to go directly to the police, but Clark County Deputy Sheriff Edward Bylsma evidently had a well honed sense for the suspicious. After receiving his burger from a drivethrough window, he stopped in a parking lot, removed the top bun, and uncovered a “slimy, clear and white phlegm glob” on the meat.

According to the Huffington Post, "Deputy Bylsma felt ill all day; he claims that he even vomited on account of his emotional distress. He sent the burger away for DNA testing to try and trace the spit back to an individual person. When the results linked the loogie to Burger King employee Gary Herb, Bylsma moved to sue Burger King. He said that he became unable to eat food from restaurants and lived in fear of contracting a foodborne illness."(How the deputy acquired a reference sample from Mr. Herb is not apparent from news accounts.)

A federal judge dismissed the 2009 case against Burger King for negligence, product liability and vicarious liability because the Washington Product Liability Act [WPLA] does not provide for damages for emotional distress in the absence of physical injury. Or so it thought. The Ninth Circuit asked the Washington Supreme Court to rule on the scope of its tort law, and last month, the state court wrote that "[t]he courts of this state recognize damages for ... emotional distress, and thus, such damages, if proved, are recoverable under the WPLA." It added that "[t]he WPLA permits relief for emotional distress damages, in the absence of physical injury, caused to the direct purchaser by being served and touching, but not consuming, a contaminated food product, if the emotional distress is a reasonable response and manifest by objective symptomatology."
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Of course, whether the deputy will recover at trial (if it comes to that) remains to be seen. Will Burger King argue that the deputy, whose job may require him to view grisly scenes of human violence and carnage, is overstating his symptoms?


Moving Violations

In England, the national DNA database has been employed to curb spitting on transit workers. As part of Operation Gobstopper, bus drivers in northwest London received 2,500 evidence collection kits. Tube staff in central London and train wardens in Scotland were similarly equipped, the BBC reported in 2004.

The kits helped prosecute about 100 people on the Tube in 2007. Reportedly, 7 out of 10 samples yielded a match to DNA profiles in the national database of criminal offenders and arrestees.

Update of Mar. 25, 2013: The Whopper case, Bylsma v. Burger King Corp., 293 P.3d 1168 (Wash. 2013), did not involve a database search. Only two employees, an Herb and a McDonald, had been working in the restaurant.When police visited the restaurant that night and asked for saliva samples, the two refused. The state crime laboratory determined that the saliva on the burger was of human origin. The police returned with search warrants, and the laboratory named Herb as the source of the spit. Herb pleaded guilty to felony assault (although the spit was not initially visible and only touched Bylsma because he placed his finger in it to test its consistency) and was sentenced to 90 days in jail. (Thanks to Jeremy Gans, whose comment provided a link to the civil complaint setting forth these facts).