Seventh Circuit Warns About Using Dual Fact / Expert Law Enforcement Testimony

Seventh Circuit finds use of dual fact and expert law enforcement testimony was error because it was unclear which parts of the expert testimony were based on fact and expert testimony, and the trial court’s failure to instruct on evaluating the opinion testimony, but the error was harmless based on overwhelming evidence of guilt, in United States v. York, 572 F.3d 415 (7th Cir. July 15, 2009) (07-2032)

Technically, under the FRE there are no pure “fact” or “expert” witnesses. Instead, the focus is on the testimony that is either factual or expert in nature. The rules recognize that the same witness can provide both types of testimony. As noted by the Advisory Committee on Rules in 2000, “it is possible for the same witness to provide both lay and expert testimony in a single case.” FRE 701 ACN (2000 Amendment) (emphasis added). While permissible, care must be exercised in using dual fact and expert testimony. A recent Seventh Circuit case identified concerns in using dual fact-expert testimony from the same witness - which in this instance turned out to be a harmless error.

In the case, defendant York was recorded in a conversation with informant Mitchell discussing the purchase of crack cocaine from York. When York proceeded to trial on crack cocaine distribution charges, the circuit noted the following problem in presenting the evidence of the crack sale:

“[T]he government played the recorded conversations [of defendant York's conversations with informant Mitchell] for the jury. Though York and Mitchell seemed to speak in plain English, without any reference to drugs, the government argued that they were really conversing in the cryptic, coded language of the narcotics trade. The government called two law enforcement witnesses to interpret this drug jargon for the jury. These interpretations made clear that York and Mitchell were negotiating a drug deal, despite their words being facially benign-e.g., ‘nine probably hard’ meant nine ounces of crack cocaine.”
York, 572 F.3d at 429.


The meaning of the code used in the recorded conversation was addressed at trial by two government witnesses. One clearly testified as an expert and confirmed the meaning of seeming innocuous words as drug code. Another agent testified as well, FBI Agent Brown, who was one of the “primary agents handling the investigation of York and who helped execute the sting.” Brown's testimony was problematic. The circuit noted that the agent's testimony:

“explained the sting operation to the jury, described what the jurors saw as they watched the video of York meeting with Mitchell, and identified the voices in the audio recordings as Mitchell's and York's.... But the government did not use Brown solely as a fact witness. Brown had extensive experience in prior drug cases. So the government, without first formally offering Brown as an expert, asked Brown to give his opinion about the meaning of certain words and phrases that Mitchell and York used in their conversations. Brown obliged: 'half' meant half a kilo of cocaine, 'nine' meant nine ounces, 'hard' meant crack cocaine, 'soft' meant powder cocaine, 'work' meant the drug business, 'cook' meant converting powder cocaine into crack, and 'boost up' meant diluting a given quantity of cocaine into a larger volume to have more to sell.”
York, 572 F.3d at 419.


After his conviction, the defendant challenged the agent’s testimony. The circuit did not find the defendant's arguments compelling with regard to whether the trial judge made the proper Daubert reliability findings for admission of expert opinion evidence under FRE 702. Neither side raised the issue at trial. The circuit noted the reasons that the testimony could be admitted as expert testimony, yet even if this had been an error, the circuit deemed that it was harmless, particularly in light of the testimony of the other witness who had been presented and qualified as an expert witness.

Undertaking a plain error analysis, based on the absence of a contemporaneous trial objection, the circuit addressed the problems inherent in the witness’s “dual testimony.” The circuit outlined a host of reasons why dual testimony, despite its convenience for a party, might not be advisable. These reasons included:

  • Jury Confusion: The witness's dual role “might confuse the jury.” York, 572 F.3d at 425 (citing United States v. Goodwin, 496 F.3d 636, 641 (7th Cir. 2007) (“We previously have held that while testimony in dual roles could be confusing, it is permissible provided that the district court takes precautions to minimize potential prejudice.”); United States v. Mansoori, 304 F.3d 635, 654 (7th Cir. 2002) (“Although we have acknowledged that there is a greater danger of undue prejudice to the defendants when a witness testifies as both an expert and a fact witness, we have also indicated that a police officer may permissibly testify in both capacities.” (internal citations omitted)
  • Undue Weight: “The jury might be smitten by an expert's “aura of special reliability” and therefore give his factual testimony undue weight.” York, 572 F.3d at 425 citing United States v. Brown, 7 F.3d 648, 655 (7th Cir. 1993) (“[W]e recognize that in a close case the danger of unfair prejudice may be heightened by the “aura of special reliability” that often surrounds expert testimony, and that jurors may tend to give such testimony undue weight. The danger of unfair prejudice is most serious where the expert also is an occurrence witness.”) (citation omitted)
  • Expectation Of More To The Story: “[T]he jury may unduly credit the opinion testimony of an investigating officer based on a perception that the expert was privy to facts about the defendant not presented at trial.” York, 572 F.3d at 425 (quoting United States v. Upton, 512 F.3d 394, 401 (7th Cir. 2008) (“But it is precisely because an expert provides much of the structure for the jury's understanding of the drug trade that courts must be mindful when the same witness provides both lay and expert testimony. The jury may unduly credit the witness's fact testimony given his status as an expert.”))

In light of these dangers, the circuit outlined three “precautions” a court might consider when faced with the prospect of allowing a witness to present both fact and expert testimony:

  1. Clarity Of Roles: “The jury needs to know when an agent is testifying as an expert and when he is testifying as a fact witness. “The potential for prejudice in this circumstance can be addressed by means of appropriate cautionary instructions and by examination of the witness that is structured in such a way as to make clear when the witness is testifying to facts and when he is offering his opinion as an expert.” Mansoori, 304 F.3d at 654.
  2. Clear Foundations: The proponent should establish “the proper foundation for the witness's expert opinions” United States v. Farmer, 543 F.3d 363, 370-71 (7th Cir. 2008) (where witness was “undoubtedly qualified” and neither party “specifically requested that the district court evaluate” the witness’s “qualifications as an expert under Rule 702” … the court is not required to undertake the FRE 702 analysis).
  3. Opportunity For Rigorous Cross-Examination: The trial judge should allow “the defense to rigorously cross-examine the expert about his interpretation of the drug lingo” if the expert is testifying as a dual witness. United States v. Parra, 402 F.3d 752, 759-60 (7th Cir. 2005) (because defense counsel “engaged in rigorous cross-examination of Agent Becka regarding his expertise and the substance of his testimony” admission of dual fact/expert testimony was not an error).

In assessing the record in York’s case, the circuit found that the “protective steps taken … were not the model of how to handle a witness who testifies in a dual capacity.” The circuit specifically noted that it was not clear if the agent was testifying as an expert or as the case agent. The prosecution’s questioning did not help much in distinguishing the expert from the fact witness role. Apparently the questions on direct were intermingled with questions based on the agent's expertise and questions about the investigation. For example, the circuit noted confusion based on the prosecutor’s question based on the agent's experience in crack investigations, and asking about the investigation.

Finally, the circuit noted that the trial judge failed to instruct the jury on how it should evaluate opinion testimony from witnesses with special knowledge at the time the witness was testifying. It was not sufficient to give the instruction only at the end of trial. The preferred approach when a dual witness testifies is to explain the witness’s dual role before the witness testifies “and then flag for the jury when [the witness] testifie[s] as a fact witness and when he testifie[s] as an expert.” York, 572 F.3d at 426.

The circuit went to considerable length to explain how “things got murky” so that in examining the record it was hard to distinguish when the testimony was in an expert capacity and when it was as a fact witness. Despite these errors, they were harmless because of the overwhelming evidence that had been properly admitted against the defendant. However, the case serves as a warning to the use of dual fact and expert testimony involving law enforcement witnesses.

For other recent cases discussing dual fact/expert witnesses, consider:

Federal Rules of Evidence
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