Category Archives: Drug Analysis/Toxicology

Language Matters: USDOJ’s Reporting Language and Testimony Guidelines

Forensic scientists are tasked with the job of explaining often complex scientific data to judges, jurors, and attorneys who may have little understanding of the science underlying the forensic analysis in a case.

Revelations in recent years that hair analysts provided testimony that had no scientific validity has highlighted the importance of using correct language to convey information about forensic analysis and its limitations. Several wrongful convictions have been overturned based on faulty testimony about hair evidence and a massive review of hair cases is ongoing.

In an effort to improve expert testimony, the U.S. Department of Justice has released proposed guidelines called the Uniform Language for Testimony and Reports. These guidelines, once finalized, will apply to all USDOJ personnel who issue reports or provide expert forensic testimony, and they will probably be viewed as best practices for the entire forensic community. The guidelines are currently accessible at, with the public comment section running through July 8, 2016.

Attorneys should be aware of these guidelines and be prepared to object to any lab report language or testimony that does not comply. For example, the Uniform Language for Testimony and Reports for the Forensic Latent Print Discipline provides the following guidance on what experts cannot say about their evidence: (1) they cannot state that two prints originate from the same source to the absolute exclusion of all other sources; (2) they cannot state that there is any statistical level of certainty attributed to their determination; (3) they cannot testify that their science is infallible. Similarly, for the testing of bodily fluids, analysts may not state or imply that a level of numerical certainty is calculated to support the identification of blood or semen (i.e., they cannot say they are 95 per cent confident that the stain contained blood or there is a one in a hundred chance that the stain was something other than semen) and may not state or imply that the methods used in performing serological examinations have error rates of zero or that they are infallible. For drug analysis, the guidelines specify that when no sampling plan was used and no reasonable assumption of homogeneity of an item was determined, the examiner may not report or state an opinion that the conclusions apply to the entirety of an item (or a percentage of the item). This limitation is important in pill cases where only one pill is tested.

So, if you have any suggestions about appropriate limitations for expert testimony, or the language they should use in reports, please take the time to provide feedback on these documents.


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Reliability Concerns Regarding Probation Drug Screens

The NC Department of Public Safety (DPS) has begun relying on less accurate presumptive testing for urine screens for drugs for probation, prison, and DSS cases. The focus of this post will be probation cases, though the testing is the same for prison and DSS cases.

Testing Prior to 2014

Until February 2014, the Department of Public Safety maintained two laboratories with trained staff and EMIT analyzers (an immunoassay test) to run either initial testing or additional testing on urine that gave a positive result on an screening test. These labs tested approximately 125,000 samples per year. The North Carolina State Crime Lab uses similar equipment to the former DPS labs for presumptive toxicology testing.

Current Drug Testing Procedures

The DPS labs were closed in early 2014. On-site urine drug screening is now performed by probation officers using a presumptive test kit similar to the type of urine dip test that can be purchased over the counter at many stores. Currently, additional testing is completed by Norchem, a private lab in Arizona, only when the test subject immediately denies use of a controlled substance. If the test subject admits use, the urine specimen is discarded and a positive result is reported (See NC DPS Division of Adult Correction and Juvenile Justice – Community Corrections – Policy & Procedures – Chapter H – Section .0400 Substance Abuse Screening Program, available at, p. 367, subsection (i)). Because the urine sample is discarded, if the test subject later denies use, the sample cannot be re-tested using more reliable methods.

Reditest and the Need for Confirmatory Testing

The Reditest Panel Dip Test (“Reditest”) is the on-site screening test currently used by probation officers. The Reditest is one of many presumptive test kits which are intended to screen for drugs in urine. The Reditest package insert which describes how to use the product states in its “Limitations” section that the test “provides only a preliminary analytical test result. A secondary analytical method must be used to obtain a confirmed result.” The instruction card for a similar product can be found here. The instructions note that gas chromatography/mass spectrometry (GC/MS) is the “preferred confirmatory method.”

Reditest and Lack of Validation and On-Site Quality Assurance and Quality Control

Reditest recommends but does not provide “positive and negative controls to be tested as good laboratory practice to confirm the test procedure and to verify proper test performance.” Reditest kits are not being validated by the end user in North Carolina. If batches of test kits are not validated, there is no check on the accuracy of kits being used in the state. Immunoassay testing performed by the DPS labs prior to 2014 revealed that on several occasions the on-site test kits shipped to probation and other offices did not work as expected and yielded either inaccurate or uninterpretable results.

To administer the Reditest, a provider dips a portion of the card in a urine sample for 15 seconds. Five minutes later the results can be obtained. The card should have a control line appear in each testing area. If any line appears in the testing section (no matter how faint), the results are negative for that screen. If a line does not appear in the testing section, the manufacturer’s website explains how to send the sample to a laboratory for confirmatory testing. Administration of these presumptive tests by probation officers instead of individuals with scientific training further complicates the potential for incorrect results.

False Positives with Reditest

Included on the package insert are a subset of clinical studies which demonstrate the preliminary nature of the test. Agreement with GCMS, a more accurate confirmatory test, ranged from 89%-99%. The numbers demonstrate the possibility for false positives. In tests such as these, a false positive is typically caused by a legal substance which the kit confuses with an illicit drug. Most commonly this involves over-the-counter medications. For example, some kits will register pseudoephedrine as methamphetamine. The FDA also notes that results from these types of tests can be affected by how the test was performed, how the urine was stored, what the person ate or drank before taking the test, and any other medications the person may have taken.

Admissibility of Screening Test Results

In State v. Carter, 765 S.E.2d 56 (N.C. App. 2014), the N.C. Court of Appeals held that field drug test kits, which are presumptive tests, are inadmissible due to their lack of reliability. The Court noted that for testing of controlled substances to be admissible, it “must be based on a scientifically valid chemical analysis[.]” To establish that a test is admissible, the party must present evidence that the test methods are sufficiently reliable. Results of these initial tests without confirmatory testing should not be admissible and should not be sufficient for the basis of revocation of probation.

Screening Tests and Workplace Testing

Use of the Reditest would not meet federal guidelines for workplace testing. The U.S. Department of Health and Human Services (HHS) 2015 Mandatory Guidelines for Federal Workplace Drug Testing requires that an initial drug test be an immunoassay or alternate technology, such as spectrometry or spectroscopy. (Section 11.9, Available at An HHS-certified laboratory must validate an initial drug test before testing specimens. (Section 11.9) Initial test results must be confirmed by an analytical method that uses mass spectrometric identification. Such methods include gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), GC/MS/MS, LC/MS/MS] or equivalent. (Section 11.12) Only specimens that yield a positive result on initial and confirmatory tests are reported as positive results. (Section 11.17)

In North Carolina, the testing used to allege a probation violation, revoke probation or remove a child from a parent’s custody would not qualify as even an initial test in the federal employment context.


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False Positives in Drug Field Testing Kits

The director of a lab recognized by the International Association of Chiefs of Police for forensic science excellence has called field drug testing kits “totally useless” due to the possibility of false positives. In laboratory experiments, at least two brands of field testing kits have been shown to produce false positives in tests of Mucinex, chocolate, aspirin, chocolate, and oregano. However, law enforcement agencies continue to employ these kits.

Fox 13 Tampa investigated the validity of drug field testing kits in the wake of arrests of three people based on false positives from field tests. Eventually all three were cleared and all charges were dropped. However, for the months between arrest and confirmatory testing by the state crime lab, the individuals felt that they were “guilty until proven innocent.”

Dr. Omar Bagasra, a research scientist at Claflin University, has been looking into the validity of field drug testing kits. In controlled tests in his laboratory, Dr. Bagasra, Dr. Cherilyn Haggen-Paey, and forensic scientist Chris Addanki, have demonstrated that the chemicals used in the kits are prone to give false positives even with common household materials. According to their tests, Mucinex can produce false positives for heroin and morphine; chocolate can be interpreted as marijuana; and soap can test positive as GHB. Even exposure to air caused false positives in some kits, according to their tests. The scientists noted that they had trouble interpreting results in a laboratory environment and “you can imagine in the field it’s even more difficult.” However, the experts say the problems are not linked to just the individual kits tested or a specific manufacturer, as many the field test kits tend to contain the same chemicals.

Field drug testing kits were created to screen for illicit substances in the field followed by more complete testing in a laboratory setting. However, the tests stand in for more scientifically valid testing until analysis at state crime labs occurs. Drug testing at state crime labs is typically performed just prior to trial due to the high rate of plea bargaining in drug cases, and therefore false positives are often not discovered unless contested at trial. During this time, the false positives from field tests can cause innocent citizens to be detained in jail for weeks or even months.

“False Positive Equal False Justice,” a 2008 report created for the California Attorneys for Criminal Justice, noted that false positives resulting in criminal charges has been an ongoing problem. In 2003, a Pennsylvania college student was held for three weeks when flour was mistaken for cocaine. In 2007, musician Don Bolles was arrested for possession of GHB which was actually soap. Additionally the report lists approximately forty extracts—such as vanilla, peppermint, or ginkgo—which can test as false positives for marijuana.

Dr. Frederic Whitehurst, a Ph.D. chemist and former FBI lab supervisor, has expressed concern with the use of field drug testing kits. He stated that he has “no confidence at all in those test kits.” Due to the high chance of false positives, both Dr. Whitehurst and Dr. Bagasra have recommended that drug field testing kits not be used. They say law enforcement would receive more valid results by waiting for results from lab testing. The kits are single use and range from a $4 to $20 a use depending on what drug is being investigated.

For more general information on forensic drug analysis see

Click here to read an article about the 2011 arrest of a man in Buncombe County based on a false positive field test result of cheese and tortilla dough.

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Admissibility of field test kit results

In State v. Carter, 237 N.C. App. 274 (2014) the NC Court of Appeals found that a trial court abused its discretion by admitting an officer’s testimony that narcotics indicator field test kits indicated the presence of cocaine on various items.

The court cited State v. Ward, 364 N.C. 133, 142 (2010) which held that “expert witness testimony required to establish that the substances introduced . . . are in fact controlled substances must be based on a scientifically valid chemical analysis[.]” In Carter, a sheriff’s deputy tested for the presence of cocaine on various items in a residence using a narcotics indicated field test kit (“NIK”). The State did not introduce evidence about how the chemical analysis worked or any testimony about the tests’ reliability apart from the sheriff’s deputy’s opinion based on his personal experience with the kits.

The court noted that the NIKs were similar to ones that have not previously been found by our courts to be a reliable method of controlled substance identification. See State v. James, 215 N.C. App. at 589, 590 (2011)  (finding the State did not sufficiently establish the reliability of [a] NIK” consisting of “small ‘moist towelette . . . about the size of a[n] alcohol wipe[]’ . . . that . . . turned blue, thereby indicating that the substance tested positive for cocaine.”)

The court relied on State v. Meadows, 201 N.C. App. 707 (2010) which held that a trial court abused its discretion by allowing an officer to testify that substances were cocaine based on NarTest field test. Attorneys should review these decisions when litigating cases where field test kits or other presumptive tests were used and consider whether the reliability of the tests can be established.


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Sample Motion for Independent Testing of Evidence

Defense attorneys may decide to make a motion for independent testing of forensic evidence in cases where either the State has chosen not to complete forensic testing of an item of evidence or where the State has tested the item and the defense would like it to be re-tested. This issue has come up more frequently in recent DWI cases where the State has elected to proceed on an “appreciable impairment” theory rather than waiting to have the blood sample tested by the State Crime Lab.

Failure to include necessary information in a motion and order for independent testing can result in delays as the evidence custodian attempts to determine how to comply with the court order that lacks information needed to ship the item of evidence to the independent laboratory. In an attempt to ensure that the necessary information is included in a motion and order for independent testing, I have drafted a sample motion and order that attorneys can adapt to their cases. Assistant Attorney General Joy Strickland has been provided an opportunity to review it and make suggested changes. Here is a link to the motion and order.

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Substitute Analyst cases update

The NC Supreme Court decided several cases in June that dealt with the admissibility of testimony by substitute forensic analysts. The lead case in this series is State v. Ortiz-Zape, a case in which a forensic chemist testified for the state regarding the results that a non-testifying analyst produced using the gas chromatograph mass spectrometer (GCMS). The Court held that allowing the testimony of the substitute analyst did not violate the defendant’s Confrontation Clause rights where the expert’s testimony was an “independent opinion based on otherwise inadmissible facts or data of a type reasonably relied upon by experts in the particular field.” Ortiz-Zapeslip op. at 13 (quotations and citations omitted). The NC Supreme Court reasoned that the defendant’s right to cross examine the expert giving the opinion, not its underlying factual basis, is guaranteed by the Confrontation Clause.

Defenders, however, should continue to make objections to the testimony of substitute analysts at trial to preserve the issue, as the U.S. Supreme Court will be the final word on this issue.

It’s important to read the further analysis of this line of cases that is provided by Jessie Smith in her North Carolina Criminal Law blog post here.  She also explains the requirements for laying a proper foundation for substitute analyst testimony and discusses impermissible “surrogate” testimony.

While the NC Supreme Court in Ortiz-Zape discusses machine-generated raw data as being “truly machine-generated,” it has been shown that the results can be manipulated. Take a look at the video on Justin McShane’s blog for one example of why it is important to be able to cross-examine the analyst who performed the testing.


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Thousands of cases compromised due to faulty forensic analysis

In recent months, faulty forensic analysis has been exposed in several labs across the country. The failure of a handful of lab analysts to correctly perform forensic analysis has compromised thousands of cases. In each situation the failures are different, but they expose a lack of oversight of analyst performance in the affected labs. The following are several of the most serious failures:

Annie Dookhan

A Massachusetts chemist was accused of faking test results at the state lab and tampering with drug evidence while she tested suspected controlled substances in criminal cases. Authorities declared that Dookhan tested more than 60,000 samples involving 34,000 defendants during her nine years at the Department of Public Health lab. Over 200 convicted defendants have been released from custody while their cases are being reviewed due to Dookhan’s involvement, according to this article. One of the red flags that lead to Dookhan’s misconduct being detected was the fact that she was highly efficient at her job; she was handling an astounding number of samples compared to an average chemist. Investigators allege that Dookhan was able to accelerate her work by “dry labbing” or reporting results for analyses that she did not actually perform. Dookhan has been indicted on 27 charges, including 17 counts of obstruction of justice, eight counts of tampering with evidence, perjury and falsely testifying that she held a degree from a college or university.

Sonja Farak

Another Massachusetts chemist that worked in the state crime lab in Amherst was arrested in January and charged with evidence tampering and possession of controlled substances from the lab, according to this article. The Boston Globe reported that Farak was discovered when her supervisors were making a routine check of tested substances and found that certain substances tested by Farak had been replaced with counterfeit substances. Attorney General Martha Coakley said that both Farak and Dookhan had begun their career at the Hinton lab in Jamaica Plain. Unlike in Dookhan’s case, supervisors noticed that Farak had had a drop in her productivity. Authorities have stated said that Farak’s misconduct was quickly detected by her supervisors, limiting the scope of its impact.

Jonathan Salvador

A forensic scientist who worked as a controlled substances analyst at the Texas Department of Public Safety (DPS) was suspended when it was discovered that he issued a fraudulent report about a batch of pills, according to this post in the Grits for Breakfast blog. The report was issued without testing the pills and instead, substituted data from another sample. The DPS characterized Salvador’s work as deficient prior to this incident. Case supervisors were aware of Salvador’s poor performance and knew that he appeared not to understand the science of the work he was assigned. However, his performance was tolerated and he would often volunteer for unwanted tasks in the lab. In its internal investigation, the DPS found several additional cases where Salvador misreported results. According to Grits for Breakfast “hundreds of convicted defendants may end up having their cases overturned, either freeing them from prison or ending their probation terms.” It was reported that hundreds of samples tested by Salvador during his six years at the DPS were being retested.

Iowa analyst fired over mishandling of fingerprint evidence

A state police crime lab analyst in Iowa was fired in January due to errors in reports related to fingerprint analysis, according to this article. The lab reviewed the analyst’s 2012 cases and found at least nine cases contained errors where the analyst had incorrectly classified fingerprint evidence as unusable. The analyst’s errors were discovered in a routine internal review of cases. The investigation of the analyst’s casework continues. The analyst had been employed by the lab for sixteen years.

Mishandling of DNA Evidence in Rape Cases

The New York City Medical Examiner’s Office is reviewing over 800 cases worked by a lab technician who resigned in 2011. According to this New York Times article, reviewers have found so far that the technician failed to detect biological evidence in 26 cases when in fact existed. Additionally, in 55 cases, the lab technician failed to upload evidence from crime scenes into the state’s DNA database. The mishandling of DNA evidence led sex-crime investigators to not have available evidence that was could have been used to develop cases against rape suspects.  Supervisors also discovered sixteen pieces of evidence that had been placed in the wrong rape kits. The majority of the misplaced items were swabs sealed in paper envelopes.  This mixing of items from different cases raises concerns about cross-contamination and whether other lab protocols were ignored.

Additional cases of lab analyst misconduct are detailed in this NACDL News Release.

In sum, it is important for the attorneys to be aware of the risks of not reviewing the lab reports, including the underlying data, in all of their cases. Although the majority of labs endeavor to monitor the work of individual analysts through case reviews, the cases above indicate that supervision cannot completely deter deficient performance by individual analysts.

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