Traditional forensic pattern-matching testimony in Williams v. United States

The opinion of the District of Columbia's highest court in Williams v. United States, 130 A.3d 343 (D.C. 2016), is straightforward, but it is worth noting a modern example of traditional forensic pattern-matching testimony.

The case

In 2010, the bullet-riddled body of Min Soo Kang was discovered on the side of a road in Southeast D.C. Police retrieved three bullets that had penetrated the driver’s seat and fingerprints from his Cadillac Escalade in Northeast D.C. A trawl of the national Automated Fingerprint Identification System (AFIS) led police to suspect Marlon Williams. Pursuant to a search warrant, police took a High Point brand firearm from the bedroom of his apartment.

Bullets tested fired from the gun had impression from passing through the barrel that matched the ones on the bullets the car. The criminalistics evidence and “the testimony of an individual to whom Mr. Williams had made incriminating statements while they were in the courthouse cellblock formed the bulk of the government's case.” Id. at 346. The case was persuasive—the jury convicted Williams of first-degree murder and other crimes.

The firearms evidence

The firearms and toolmark examiner, Luciano Morales, testified on direct examination that when a bullet is fired from a particular gun, the gun leaves “unique” identifying marks, “similar to a fingerprint, basically.” He then testified that he had compared the markings on the bullets recovered from Mr. Kang's car with the markings on the bullets test-fired from the gun recovered from Mr. Williams's apartment (manufactured by High Point and admitted as Exhibit No. 58), and he had concluded that the bullets were fired by the same gun. On redirect, when the prosecutor asked whether there was “any doubt in [his] mind” that the bullets recovered from Mr. Kang's Escalade were fired from the gun found in Mr. Williams's room, the examiner responded, “[n]o sir.” He elaborated that “[t]hese three bullets were identified as being fired out of Exhibit No. 58. And it doesn't matter how many firearms High Point made. Those markings are unique to that gun and that gun only.” The prosecutor then asked the examiner whether, “judging from the markings that you find in 58, it's your conclusion that those three bullets were fired from 58?” The examiner was unequivocal: “Item Number 58 fired these three bullets.”

Id. The Court of Appeals held that the admission of this testimony was not error—because defense counsel did not object to it at the trial. Of course, the court recognized a standard exception to the need for a contemporaneous objection—the "plain error" rule. However, under this exception, “it is not enough for an appellant to demonstrate error; the appellant must also show that the error is ... ‘so egregious and obvious as to make the trial judge and prosecutor derelict in permitting it, despite the defendant's failure to object.’” Id. at 347.

Some readers might think that resorting to hyperbole could amount to a dereliction of a prosecutor's duty not to overstate its case and of an expert's obligation to stay within the bounds of what the expert discipline validly can claim to know. Indeed, the government conceded on appeal “that, at Mr. Williams's trial, it violated its policy ‘to only elicit firearms examiners' opinions to a reasonable degree of scientific certainty.’” Id. at 348. But the court balked at the idea that the trial judge should have demanded the phrase “reasonable scientific certainty.” It noted that

[W]e question whether this court would want to endorse a policy of “only elicit[ing] firearms examiners' opinions to a reasonable degree of scientific certainty,” in light of criticism that firearms examination does not involve any “scientific” measure of certainty. See National Research Council, Committee on Identifying the Needs of the Forensic Sciences Community, Strengthening Forensic Science in the United States: A Path Forward 154–55 (2009); National Research Council, Committee to Assess the Feasibility, Accuracy, and Technical Capability of a National Ballistics Database, Ballistic Imaging 3, 81–82 (2008).

Id. at 348 n.11.

The "reasonable scientific certainty" mantra definitely has its problems, 1/ but the better argument was that the dereliction of duty evident in Williams was not the kind of error that could satisfy the plain-error doctrine: “The government's internal policy does not constitute binding law—let alone a ‘clear’ or ‘obvious’ rule—that a trial court should be presumed to know.” Id. at 348–49 (notes omitted). “[O]nly when an error is ‘clear under current law’ can it be “plain.” Id. at 347.

But what is "current law"? Does it take a previous opinion in the same jurisdiction to make a proposition "clear under current law," or can the result clearly be immanent the fabric of such opinions, or even in those of other jurisdictions?

Although not without ambiguity, the opinion seems to accept the latter, more expansive understanding of "current law." First, it reads its previous opinions as too tentative or reserved to establish a legal rule precluding testimony of 100% confidence.

The closest this court has come to addressing this issue was in (Ricardo) Jones v. United States, 27 A.3d 1130 (D.C.2011). In that case the defense argued inter alia that toolmark and firearms examiners could not “stat[e] their conclusions with ‘absolute certainty excluding all other possible firearms.’ ” Id. at 1138. In response, the government assured this court, both in its appellate brief and at oral argument, that it was the government's policy not to present such testimony. “In light of the government's representation,” this court “assume[d], without deciding, that such experts should not be permitted to testify that they are 100% certain of a match, to the exclusion of all other firearms.” Id. at 1139. The court then determined that any such error was harmless. Id. Jones did not plainly bar the toolmark examiner in this case from testifying as he did and does not provide a foundation for a determination of plain error.

Id. at 348. Thus, “[t]here [was] no precedent in this jurisdiction that limits a toolmark and firearms examiner's testimony about the certainty of his pattern-matching conclusions.” Id. at 347-48. Although the court was willing to consider "the weight of non-binding authority outside this jurisdiction," it could locate very few appellate opinions condemning expressions of absolute certainty. Id. at 348. Hence, Williams’ objection, raised for the first time on appeal, came too late.

The future

If Williams had objected at trial, would it have made any difference to the outcome? The established view is that the expert can express total certainty in a “unique” identification. But if the expression of 100% confidence in Williams is legally (or professionally) unpalatable (as a concurring opinion by the author of the panel opinion suggested), how should a firearms examiner testify? The legal contrivance of “reasonable scientific certainty” is not a viable alternative. 1/ Statements about “likelihoods”—the probabilities of the matching patterns being seen (1) when the sample gun fires the bullet, and (2) when different guns fire the bullet—are widely recommended by students of forensic inference. Subjectively assessed likelihoods are appealing if they are frankly and transparently explained and the expertise underlying them has been demonstrated to exist. In the longer term, will efforts to achieve objective measurements and to use machine learning or other statistical tools to quantify the likelihoods for those measurements 2/ lead to a better, or at least a complementary approach?

Notes

1. See Is "Reasonable Scientific Certainty" Unreasonable?, Forensic Sci., Stat. & L., Feb. 26, 2016, http://for-sci-law.blogspot.com/2016/02/is-reasonable-scientific-certainty.html .
2. John Song, Xiaoping Liu. A Review of NIST Projects in Surface and Topography Metrology for Firearm Evidence Identification in Forensic Science, 1 J. Sci. & Industrial Metrology 1 (2016); T.V. Vorburger et al., Topography Measurements and Applications in Ballistics and Tool Mark Identifications, Surface Topography: Metrology and Properties, Dec. 17, 2015, http://iopscience.iop.org/article/10.1088/2051-672X/4/1/013002

Having trouble finding this blog?

The URL for Forensic Science, Statistics, and the Law blog has changed,
from http://for-sci-law-now.blogspot.com/ to http://for-sci-law.blogspot.com/ .
Sorry for the inconvenience.

Proposed Uniform Language for Forensic Serology

The second document listed in the announcement of "Uniform Language" (UL) documents for forensic science is the “Proposed Uniform Language for Testimony and Reports For the Forensic Examination of Serology.” It pertains to the detection of sera, not the examination of serology, but you get the idea. The task is one of classification: Is this a blood stain? Is it a semen stain?

The approved statements (with emphasis added) are

• blood or semen may be present on an item of evidence [using "the appropriate presumptive testing procedure(s)"]
• blood or semen was identified on an item of evidence [using "the appropriate confirmatory procedure"].

In terms of accuracy, the difference between "presumptive" and "confirmatory" is that presumptive tests are less specific — more substances will be test positive with a presumptive test. A supporting document explains that confirmatory testing can include either a highly specific test — or just a second, presumptive test, if based on “different chemical principles” and “not subject to the same limitations.” (Or maybe a second and a third screening test are required; it is hard to tell from the document.)

Although the examiner is not allowed to say that a positive result is "infallible," that is only because an examiner might goof in following a protocol that is perfectly discriminating. The confirmatory procedure “identif[ies] blood or semen to the exclusion of all other substances.” (P. 5.)

The documents display little sympathy for probabilistic thinking. Apparently, examiners may not give an error probability for an "identification," for "the analytical processes and procedures ... do not have a calculable error rate due to the unpredictability of human error." This observation motivates the proscription of statements of a "zero error rate," but by this logic, the probability of commercial pilot error, of a mishap in a nuclear power plant, or of medication errors in ICUs could not be calculated.

Aside from this allegedly unquantifiable risk of strictly "human error," identifications are subject to no uncertainty:

• when crystals are formed under the proper testing conditions, there is no doubt of the nature of the stain tested ... no false positives.
• [if] the Takayama test ... is positive, blood is conclusively present.

Despite this certitude in the supporting document, the UL document itself cautions that

An examiner may not state or imply that a level of numerical certainty is calculated to support the identification of blood or semen.

The claims of "no doubt" and "conclusively" positive results can be reconciled with the prohibition on what can be said or reported; after all, that the number corresponding to certainty is not "calculated" is literally true. But if the examiner can report that (1) the testing conditions were proper, (2) a positive result means that "blood is conclusively present," then why cannot the examiner state that (3) "my tests demonstrate that the stain surely contains blood — the probability is 1 — unless I have done something wrong"? An argument might be that expressing conditional certainty as the number 1 is not necessary and might unduly impress readers of reports or legal factfinders.

Closely related postings

• Proposed Uniform Language for Forensic Toxicology, June 6, 2016, http://for-sci-law.blogspot.com/2016/06/proposed-uniform-language-for-forensic.html
• The Department of Justice's "Proposed Uniform Language for Testimony and Reports," June 4, 2016, http://for-sci-law.blogspot.com/2016/06/the-department-of-justices-proposed.html

More NCFS Draft Documents Released for Public Comment

The National Commission on Forensic Science (NCFS) has released nine new initial draft documents for public comment. A list of these subcommittee documents and some excerpts from each are reproduced below.The comment period will close on July 5, 2016.

★ Proficiency and Other Testing of Examiners

Subcommittee on Accreditation and Proficiency Testing, Initial Draft Recommendation to the Attorney General on Proficiency Testing, May 19, 2016, DOJ-LA-2016-0011-0004

The National Commission on Forensic Science recommends that the Attorney General:
• Recommendation #1: Require all DOJ FSSP’s to participate in a proficiency testing program applicable to the area(s) in which they conduct forensic analysis within three years of acceptance.
• Recommendation #2: Encourage other federal, state & local FSSP’s, to participate in proficiency testing programs by all means possible, with any available enforcement mechanism.
• Recommendation #3: Require all DOJ FSSP’s to seek proficiency testing programs that provide sufficiently rigorous samples that are representative of the challenges of forensic casework.
• Recommendation #4: Encourage external vendors that provide proficiency tests to DOJ to share their aggregate data with entities doing research and analysis.

Subcommittee on Human Factors, Initial Draft Views of the Commission on Optimizing Human Performance in Crime Laboratories through Testing and Feedback, May 16, 2016, DOJ-LA-2016-0011-0010

Overview: How might testing be done to assess and improve the performance of forensic science service providers (FSSPs) on routine analytic tasks? What kind of testing programs will be most helpful for achieving goals such as: (1) establishing the conditions under which analytic methods can (and cannot) be expected to achieve accurate results; (2) providing feedback to help examiners improve their skills; (3) estimating the rate of error for routine analytic tasks and better understanding variables that affect the rate of error? What steps should be taken to facilitate the development of effective performance testing in forensic laboratories in order better to achieve such goals?

★ Certification of Examiners

Subcommittee on Accreditation and Proficiency Testing, Initial Draft Views of the Commission on Certification of Forensic Science Practitioners, May 13, 2016, DOJ-LA-2016-0011-0003

It is the view of the Commission that forensic science agencies should
• Determine applicability of certification depending on the job responsibilities of the specific individual and the availability of certification programs, including but not limited to, managers, analysts and technical support.
• Develop a process that ensures all practitioners apply for certification, if a program is available and provide time and resources to achieve and maintain certification.
• Include certification requirements in position descriptions, where possible.
• Provide similar support to practitioners, if there is not a certification program available in a specific category of testing, to maintain knowledge and skills.
It is the view of the Commission that all forensic science practitioners should:
• Become certified in all categories of testing in which examinations are performed as soon as the requirements of the certification body are met, provided a certification examination is available.
• Obtain certification within five years from implementation of this document. Personnel entering the field after implementation shall obtain certification within one year of eligibility or within the required time limit of the certifying body.

Subcommittee on Accreditation and Proficiency Testing, Initial Draft Views of the Commission on Accreditation and Recognition of Forensic Science Certification Bodies, May 13, 2016,  DOJ-LA-2016-0011-0002

It is the view of the Commission that certification bodies should:
• Seek compliance to ISO/IEC 17024 Conformity Assessment – General Requirements for Bodies Operating Certification of Persons. This process should be accomplished within ten years of implementation.
• Be accredited in accordance with the requirements of ISO/IEC 17024 by an accreditation body, operating in accordance with ISO/IEC 17011 – General Requirements for Accreditation bodies Accrediting Conformity Assessment bodies and signatory to the International Accreditation Forum (IAF) Multilateral Recognition Arrangement (MLA)..
• Collaborate with other certification bodies to develop uniform certification requirements.
• Ensure that certification examinations are continually reviewed to incorporate new technologies and remove obsolete information.

★ Accreditation

Subcommittee on Accreditation & Proficiency Testing, Initial Draft Views of the Commission Regarding Accreditation Program Requirements, May 16, 2016,  DOJ-LA-2016-0011-0005

It is the view of the National Commission on Forensic Science that the overall accreditation of forensic science service providers could be strengthened by, at a minimum, full compliance with ISO/IEC 17011 for all accrediting bodies offering services to forensic science service providers. Further improvements could be achieved with the consistent adoption/incorporation of the following requirements by accrediting bodies:
• Shorten the time period between on-site assessments.
• Require surveillance visits every year a facility does not have a full assessment.
• Expand the requirements of ISO 17011 definition of surveillance visits.
• Ensure appropriate technical assessors for categories of testing conduct assessments. (Assessors should have recent work as an analyst in the discipline.)
• Require accrediting bodies to provide continuous training and feedback to assessors.
• Incorporate unannounced visits/assessments.
• Include targeted and random sampling as well as case observations/witnessing when reviewing casework.
• Develop standards for sampling plans that account for casework volume and number of analysts.
• Increase the number of annual case observations/witnessing.
• Increase the percentage of technical reviews.
• Require a specific percentage of blind re-examinations.
• Increase requirements for proficiency testing plans (e.g. number of external per year/cycle based on a percentage of analysts.)
• Increase the robustness of the testimony monitoring program including in-person monitoring and transcript review with a mandated frequency.
• Require method validation to include both external sources/studies of the overall performance and reliability and internal studies of appropriateness and performance.
• DOJ should seek aggregate data issues/non-conformities from all assessments of forensic science service providers from each accrediting body. Anonymity and confidentiality should be maintained as the purpose of the report is to review systemic issues in forensic science that should be addressed.
• DOJ should encourage continuous improvement of the accreditation process and provide support through funding, research and other initiatives.

★ Case Reporting and Records

Subcommittee on Reporting and Testimony, Initial Draft Recommendation to the Attorney General on Documentation, Case Record and Report Contents, DOJ-LA-2016-0011-0007

The National Commission on Forensic Science recommends that the Attorney General have Department of Justice Forensic Science Service Providers (FSSPs) develop and maintain written policies for documenting the examination, testing, and interpretation of evidence and for reporting results, interpretations, and conclusions that are consistent with the following requirements:
1. Records should be created during the examination of evidence and the technical review that allow another analyst or scientist, with proper training and experience, to understand and evaluate all the work performed, and independently analyze and interpret the data and draw conclusions.
2. Providing all of the documentation described above in a single report in every case is impractical. Instead, if not in the report, the documentation described herein must be maintained in a case record.1 Generic documentation such as Standard Operating Procedures and definitions must either be a part of the case record or be easily accessible (e.g., posted on a website, available on request).
3. Reports should clearly state: the purpose of the examination or testing; the method and materials used; a description or summary of the data or results; any conclusions derived from those data or results; any discordant results or conclusions; the estimated uncertainty or variability; and possible sources of error and limitations in the method, data, or conclusions.
4. Every report should state that the report does not contain all of the documentation associated with the work performed and that to understand and evaluate all the work performed, and independently analyze and interpret the data and draw conclusions requires a review of the case record.
5. The case record should be organized and made available in a manner consistent with the discovery recommendations of the National Commission on Forensic Science.

Subcommittee on Reporting and Testimony, Initial Draft View of the Commission on Report and Case Record Contents, April 23, 2016, DOJ-LA-2016-0011-0006

It is the view of the National Commission on Forensic Science that a report and a case record describing the results of forensic testing should, at a minimum, contain the information identified in Appendix A.

★ Medicolegal Death Investigation

Subcommittee on Medicolegal Death Investigation, Initial Draft Recommendation to the Attorney General for the Formation of a National Office for Medicolegal Death Investigation, May 18, 2016, DOJ-LA-2016-0011-000

The National Commission on Forensic Science recommends that the Attorney General take the following action(s):
Recommendation #1: The Attorney General should work with the Whitehouse Office of Science and Technology Policy¡|s Medicolegal Death Investigation Working Group and other federal agencies and professional organizations to develop a permanent National Office of Medicolegal Death Investigation which would coordinate ongoing support of the nation¡|s medicolegal death investigation systems to improve quality, consistency and the meeting of criminal justice and public health needs. Such support would not only be for daily and routine operations, but for development and implementation of new technologies, equipment, personnel, and the fostering of research with federal funding and agency support.
Recommendation #2: The Attorney General should, through the National Office in conjunction with the National Institute of Justice, recommend ongoing funding and support to improve the recruitment and retention of forensic pathologists, modernization of facilities and creation of facilities in underserve areas, accreditation of medicolegal offices and certification of its personnel, and the establishment of a national information network for the nation’s medical examiner and coroner offices.

Subcommittee on Medicolegal Death Investigation, Initial Draft Views of the Commission Regarding Communication with Next of Kin and Other Family Members, May 16, 2016, DOJ-LA-2016-0011-0009

Currently, many medicolegal death investigation offices lack policies and procedures relating to the communication and interactions they have with Next of Kin (NOK) and other family members during death investigations. (1) Additionally, accreditation standards do not directly address this issue and therefore inconsistencies exist that greatly impacts the individual family, the investigation and our society overall.

Proposed Uniform Language for Forensic Toxicology

The first document listed in the announcement of "Uniform Language" (UL) documents for forensic science is the Department of Justice Proposed Uniform Language for Testimony and Reports for the Forensic Toxicology Discipline.  At first glance, it seems rather bland, but if the document truly demarcates the range of the "acceptable range of opinions" that DoJ toxicologists may provide, it is impoverished.

For example, the Supporting Documentation observes that "[a]n examiner may be asked if certain symptoms are consistent with those caused by a particular drug," but for decades, forensic scientists, statisticians, lawyers, and psychologists have complained that "consistent with" testimony is vacuous. Evidence usually is consistent with more than one hypothesis. Drowsiness is consistent with ingestion of barbituates, but it also is consistent with lack of sleep. For the symptoms to be probative of some hypothesis, alternative hypotheses must be considered. Diagnosticity depends on the probability of the symptoms under all the hypotheses.

The proposed uniform language obscures this fundamental concept. For example, the UL document provides that an "examiner may ... state that a reported blood concentration is within the therapeutic range, toxic range, or consistent with reported fatal concentrations" and "that a drug or poison found in a hair specimen is consistent with exposure (either ingestion or environmental) to the drug or poison." If a measured concentration falls into the range within which a poison has killed someone in the past, the "blood concentration" (more precisely, the concentration of the poison) would be "consistent with reported fatal concentrations." But it may be that this "fatal concentration" is rarely fatal and is "consistent with" an alternative cause of death. Surely, a toxicologist should be permitted to say as much "based on data published in peer reviewed literature or other authoritative sources."

At the other pole, suppose the concentration is even higher than any fatal dose ever reported. The toxicologist should not be limited to the uniform language. In this situation (and in some less extreme ones), an expert can give a more powerful, useful, and scientifically accurate opinion than "consistent with."

The UL also (inelegantly) cautions that "[a]n examiner may not report or state an opinion that suggests his/her interpretation of the effects of a drug or poison can be specified to the individual whose sample was tested." Does this mean that the toxicologist can say "the defendant had a blood alcohol level [BAC] that indicates intoxication" but cannot say that "the defendant had a blood alcohol level that indicates she was intoxicated"? Both opinions express (or should express) the same idea — that the measured BAC is more probable when the defendant is intoxicated than when the defendant is not intoxicated. (If this statement about probabilities does not hold, then the BAC does not support the hypothesis of intoxication and hence does not indicate intoxication.)

The UL document first suggests that the toxicologist can only speak of "the average human." Then it redefines the average human to be someone exactly like the defendant in our example:

An examiner may report and/or state his/her opinion as to the effects of drugs or poisons on the average human. This opinion should be based on the facts of the case, medical information about the individual that the specimens were collected from (e.g., weight, height, disease state, age), current published studies, and/or the examiner’s training in the fields of pharmacology, physiology, pathology, clinical chemistry, and/or toxicology.

So the examiner must use all "facts of the case" and all the anatomical and physiological variables specific to the defendant but must not say that the opinion pertains to the defendant? Even if the toxicologist hews to this line, what happens when defense counsel asks the expert whether focusing on the defendant by using all the information about the case exceeds the admonition to confine the testimony and reporting to "the average human"? The phrasing in this paragraph needs refinement if not rethinking.

Closely related postings

• The Department of Justice's "Proposed Uniform Language for Testimony and Reports," June 4, 2016, http://for-sci-law.blogspot.com/2016/06/the-department-of-justices-proposed.html

The Department of Justice's "Proposed Uniform Language for Testimony and Reports"

The US Department of Justice (DoJ) has "Proposed Language Regarding Expert Testimony and Lab Reports in Forensic Science." The public comment period on www.regulations.gov closes July 8. Because words are the subject of the "Uniform Language" documents, as they are styled, it may be appropriate (if somewhat tedious) to jot down a few notes in the manner of English composition teachers. Readers who want remarks on the substantive merits of the documents will have to wait. 1/ What follows is merely about clarity of expression and ugliness (words like and "his/her" and "and/or").

To begin with, an initial disclaimer, boxed and bolded in the original, reads as follows:

This document provides examples of the scientifically-supported conclusions and opinions that may be contained in Department of Justice reports and testimony. These examples are not intended to be all inclusive and may be dependent upon the precedent set by the judge or locality in which a testimony is provided. Further, these examples are not intended to serve as precedent for other forensic laboratories and do not imply that statements by other forensic laboratories are incorrect, indefensible, or erroneous. This document is not intended to, does not, and may not be relied upon to create any rights, substantive or procedural, enforceable by law by any party in any matter, civil or criminal, nor does it place any limitation on otherwise lawful investigative and litigative prerogatives of the Department.

What would a careful copy editor have to say about this?

• First sentence. The documents do not give examples of scientifically-supported statements. They give (1) examples of conclusions and (2) sometimes specify the kind of scientific support that would be needed for some of them. The toxicology "Uniform Language" document, for example, refers to "analytical findings" without regard to the scientific basis of the analyses. Surely not every conceivable analytical method is scientifically adequate. (As I said at the outset, this is just a problem with the wording of the introductory disclaimer. I am not suggesting that the analytical methods currently employed by DoJ toxicologists are invalid. In fact, separate "Supporting Documentation" asserts that every one has been validated. However, the introductory statement refers to "this document," and the Uniform Language document does not constrain the range of conclusions about "analytical findings" to scientifically supported ones. In comparison, it states that "[t]he examiner may report and/or state the pharmacokinetic and pharmacodynamic effects of drugs and poisons based on data published in peer reviewed literature or other authoritative sources.")
• Second sentence. "The examples are not intended to be all inclusive" of what? Of "the scientifically-supported conclusions and opinions that may be contained in Department of Justice reports and testimony"? Presumably, this clause is meant to say that "The list of permissible statements is not exhaustive. Other statements might be acceptable."
• Second sentence (con't). "These examples ... may be dependent upon the precedent set by the judge or locality in which a testimony is provided." Stilted language ("may be dependent on") aside, the examples are examples — regardless of local law. The scientifically supportable ones in "this document" are examples of scientifically acceptable statements for the field without regard to their admissibility. The unacceptable ones should be scientifically unacceptable regardless of what a trial judge (whose rulings are not technically "precedent" for any other case) or other judges, lawyers, or legislatures do.
• Third sentence. "[T]hese examples are not intended to serve as precedent for other forensic laboratories and do not imply that statements by other forensic laboratories are incorrect, indefensible, or erroneous." DoJ has no power to make legal precedent. That it considers specific statements unfit for use by its laboratories surely has implications. Presumably, the sentence is meant to state the obvious — that DoJ's adoption for its laboratories of this list of acceptable and unacceptable examples is not intended to require other laboratories to do anything.
• Final sentence. "This document is not intended to, does not, and may not be relied upon to create any rights, substantive or procedural, enforceable by law by any party in any matter, civil or criminal ... ." But any judge is free to rely on this document to create an enforceable right. Presumably, the intended meaning is that the document, in itself, does not create such a right.
• Final sentence (cont'd). "nor does it place any limitation on otherwise lawful investigative and litigative prerogatives of the Department." What is the function of "otherwise lawful"? Naturally, the draft document places no limitation on anything DoJ wants to do. Does the full sentence mean that after adopting these guidelines, DoJ lawyers and laboratory staff will be free to depart from them? I think it means that the document is for internal guidance only and is not intended to be enforceable by any litigant.

Of course, the box of disclaimers at the beginning of each documents is just boilerplate. But skimming a couple of the Uniform Language documents also shows room for improvements in the mechanics of the writing. Here are some examples:

• Extensive use of the barbarism "and/or" 2/ and an occasional "his/her." 
• The phrase "[a]n examiner may state or imply" is common. Inasmuch as any examiner who legitimately may state that a proposition is true also may imply that it is true, "may state" the phrase "or imply" is surplusage. 3/
• Another common locution is "This document provides the acceptable range of opinions expressed in both laboratory reports and during expert witness testimony ... ." I think this is intended to state that "This document specifies the range of opinions that examiners may provide in laboratory reports or expert testimony." (It is not the "range" that is acceptable — it is the opinions.)
• The last statement is always qualified by the clause "while acknowledging that this document cannot address every variable in every examination." The qualification seems pointless or obscure. What does "address" mean here? Who would have imagined that the Uniform Language documents are supposed to address "every variable" in every forensic test, method, or analysis? If attention should have been given to an important "variable" but was not, how can we know that the range of opinions allowed is appropriate?

NOTES

1. Update: Remarks on a few of the discipline-specific documents are at

• Proposed Uniform Language for Forensic Toxicology, June 6, 2016, http://for-sci-law.blogspot.com/2016/06/proposed-uniform-language-for-forensic.html;

2. Bryan A. Garner, A Dictionary of Modern Legal Usage 56 (2d ed. 1995) (observing that "and/or has been vilified for most of its life—and rightly so. ... 'the only safe rule to follow is not to use the expression in any legal writing, document or proceeding, under any circumstances.'") (quoting Dwight G. McCarty, That Hybrid "and/or," 39 Mich. State B.J. 9, 17 (1960)); Leslie O’Flahavan, Is Using "and/or" in a Sentence Just Plain Dumb?, Jan. 25, 2010, http://ewriteonline.com/writing-matters/2010/01/using-andor-in-a-sentence-is-just-plain-dumb/ (surveying advice from journal editors and others and concluding that "the verdict is in: and/or is JPD (just plain dumb)").

3. The situation with "may not state or imply" is different.