The odds of admitting expert testimony are stacked against defendants in criminal cases. An analysis of federal criminal prosecutions found that judges almost always admit expert testimony offered by prosecutors but usually disallow the expert testimony of defense experts.

Prosecutors commonly rely on police officers to provide expert testimony. While the officers are not allowed to testify that a defendant is guilty (an issue that only the jury can decide), they are often allowed to give “ultimate issue” testimony that invites the jury to find guilt. To a jury, there is little difference between testifying that “In my opinion, the defendant sold drugs” and testifying that “In my expert opinion, all of the evidence is consistent with the defendant selling drugs.”

Federal courts have been criticized for their lax application of the Daubert standard to police officer testimony. Other experts are required to demonstrate that they formed opinions through the reliable application of a sound methodology to sufficient facts. Police officers are often allowed to couch any opinion as an expert opinion simply by claiming that the opinion is based on their experience in law enforcement.

A common example of the lax application of Daubert involves “expert” testimony about the meaning of “drug jargon.” A recent decision of the U.S. Court of Appeals for the Seventh Circuit determined that police officers can offer expert opinions about the hidden meaning of ordinary words that a defendant uses in text messages.

Facts of the Case

Maurice Gardner was the passenger in a car that was stopped by police officers in Evansville, Illinois. For reasons that the appellate opinion does not explain, the officers searched the vehicle. They found bags containing six grams of methamphetamine, digital scales, and a loaded firearm. Officers testified that they asked Gardner why he was in the vehicle and Gardner admitted that he was trying to sell drugs.

Given those facts, the government had a slam dunk case on the drug charges. It nevertheless bolstered its evidence by calling Evansville Police Officer Cliff Simpson as an “expert in narcotics distribution.” Since the jury was just as capable of interpreting the evidence as Simpson, this was not the kind of case in which the testimony of an “expert in narcotics distribution” would normally be admissible. The prosecution, however, wanted Simpson to “translate” text messages on Gardner’s phone that the prosecution claimed were “coded.”

Simpson claimed expertise because he had “interpreted” text messages and phone calls in more than a dozen wiretap investigations. The prosecution apparently offered no evidence that Simpson had interpreted the communications accurately.

Expert Opinions

Gardner received a text message that said “she will pay 245 for it.” Simpson testified that the message meant “someone would pay $245 for methamphetamine.” Since neither “245” nor “it” are drug jargon, it is difficult to understand why the judge felt that an expert was needed to decode the message. Whether “it” referred to methamphetamine was an inference that the jury could draw without Simpson’s guiding hand.

The same is true of Gardner’s reply: “I can do one for 250 and dat’s all.”  The phrase “do one” likely means “sell one” in context, but there’s nothing coded about that language. Simpson’s testimony that Gardner meant that he was willing to sell a quantity of the drug for $250 hardly requires an expert interpretation.

Simpson might have relied on expertise when he testified that 3 grams of methamphetamine would retail for $250, but the message did not say “I can sell three” or “I can sell an eight ball” (jargon that describes an eighth of an ounce, or about 3.5 grams). The jury was just as capable as Simpson of inferring that “one” referred to an unspecified drug quantity.

Finally, Gardner texted, “I ain’t got dat kind of deal rite now. I’m grinding dis out.” Simpson believed “dat kind of deal” referred to a lower price, an obvious conclusion that requires no expertise.

Simpson also testified that “grinding dis out” meant that Gardner was not selling large amounts but was breaking down his supply to sell in smaller amounts. Perhaps that’s true. Or perhaps Gardner was saying that he was just trying to get through the daily grind of his day. It is not at all clear that Simpson’s opinion about the meaning of Gardner’s words was grounded in expertise rather than assumptions.

Daubert Challenge Rejected

Perhaps the common practice of street dealers to make more money by risking multiple smaller sales rather than giving a quantity discount for a larger sale is not a practice that juries would understand without expert testimony. But Simpson did not explain how street dealers work. He simply offered a personal opinion of what “grinding dis out” meant. A reasonable expert methodology would require the expert to study the jargon used by drug dealers and to identify other instances in which “grinding dis out” meant “selling smaller quantities.” Nothing in the appellate opinion suggests that Gardner based his opinion on a reasonable methodology.

The appellate court nevertheless concluded that a different standard of reliability applies when an expert witness is a police officer. The expert officer does not need to employ a reasonable methodology to arrive at a reliable opinion. It is enough for the officer to base an opinion on the officer’s experience. The court held that “the reliability of the expert’s methods may reasonably be inferred from the expert’s background.”

Experts who testify about harms caused by dangerous drugs and toxic exposures need to rely on reasonable methodologies, no matter how “vast” their experience might be. Why is the Daubert rule different for the police? The Seventh Circuit made no attempt to justify its application of a different standard that benefits the prosecution in criminal cases. A cynic might conclude that the court simply wanted to make it easier for the government to win criminal cases and abandoned doctrinal consistency to advance that goal.

The court also rejected the argument that “Simpson interpreted innocuous, everyday words that need not be decoded by an expert.” According to the Seventh Circuit, words that might “seem entirely innocuous” to ordinary jurors can be recognized as “drug jargon” by police officers. Perhaps there are instances where that might be true, but nothing in the phrase “I can do one for 250” even remotely qualifies as coded drug jargon. What Gardner meant by “one” is an inference to be drawn from all the facts. It is not a “coded” word that only an expert can interpret.

In the end, the case against Gardner was so strong that Simpson’s testimony likely had no impact on the verdict. The court of appeals covered itself by noting that the district court’s decision to admit the testimony would have been a harmless error even if the appellate court had found the decision to be erroneous. The decision nevertheless provides further support for the sad conclusion that “the Daubert revolution, aimed at upgrading the quality of expert evidence, has had surprisingly little impact in the criminal courts.”