Law Enforcement Expert’s Testimony on the Unique Overdose Risk of Fentanyl Excluded
Posted on September 2, 2025 by Expert Witness Profiler
David James Michael Jensen is charged in an eight-count Superseding Indictment with five counts of Unlawful Possession of a Firearm, one count of Possession of Controlled Substances with Intent to Distribute (methamphetamine and fentanyl), one count of Carrying a Firearm During and in Relation to a Drug Trafficking Crime, and one count of Possession of Fentanyl with Intent to Distribute for events that occurred on five separate dates.
The Government provided Jensen’s counsel with notice of potential expert testimony by Homeland Security Investigations Supervisory Special Agent Marco Dkane about criminal practices with respect to drugs and guns to be presented at trial.
Jensen filed a motion requesting the exclusion of testimony from Dkane about common methods and practices of drug dealers.
Law Enforcement Expert Witness
Agent Marco Dkane is a twenty-two year veteran of Homeland Security Investigations (“HSI”) with the United States Department of Homeland Security.
His duties as a supervisory special agent include serving as Task Force Commander of a High Intensity Drug Trafficking Area Task Force, supervising investigative activities of narcotics agents and detectives from numerous agencies, instructing HSI investigators in narcotics investigations, and serving as a witness relating to drug trafficking method and trends. His investigative duties include conducting investigations of fentanyl, counterfeit pharmaceuticals, heroin, methamphetamine, cocaine, and MDMA (ecstasy) trafficking.
He has also served as an instructor for both local and national law enforcement training on counterfeit medications, contraband/narcotics, investigative techniques, and Organized Crime Drug Enforcement Task Forces. Dkane has been involved in the investigation of transnational criminal organizations and drug trafficking organizations. He has served as an expert witness in jury trials where his testimony included explaining the practices of drug traffickers.
Discussion by the Court
Rule 702 Challenge
1. Relevance
a. General Relevance Challenge
Jensen challenged the expert testimony proffered by the Government because he asserted that this case involved no complex illegal activities that require expert guidance. However, the Ninth Circuit has repeatedly allowed expert testimony regarding modus operandi in cases where defendants have been charged with possession with intent to distribute drugs or possession of a firearm in furtherance of a drug trafficking crime, as Jensen is charged in this case.
The Court found that Dkane’s testimony is generally relevant and will help the jury understand the evidence or determine a fact in issue.
b. Specific Relevance Challenges
(1) Matters of “Common Knowledge” to Jurors
Jensen asserted that parts of Dkane’s proffered opinions are “matters of common knowledge familiar to jurors,” “at least for those who have read a newspaper, seen a movie, or watched television since 1960 or so.”
In this case, the Government proffered that Dkane will testify about the difference between distribution and user amounts of drugs and provide other details relevant to the distribution counts.
During a search incident to arrest on April 7, 2022, officers found over $1,000 in low-denomination bills on Jensen, and a search of his vehicle found weapons and a safe containing 528 fentanyl pills, 75 grams of methamphetamine, and 22 grams of heroin in the trunk of a vehicle he had accessed moments earlier. The Government asserted that the jury is entitled to hear Dkane’s opinion as to, for example, whether 400 pills is a distributor’s or user’s quantity of fentanyl possession, information that is beyond the common knowledge of most individuals. The Court agreed that this type of information “supplements lay understandings about drug dealing and is a far cry from what is commonly known.”
(2) Types of Controlled Substances and Drug Use
Jensen asserted that the proffered opinion regarding the types of controlled substances largely consists of facts that “are both unassailable and immaterial to any issue in the case. . . . Fascinating, I suppose, in a Discovery Channel documentary way, but wholly unconnected with the facts of this case.” The Government responded that Jensen’s argument ignored the fact that he was found with the drugs that will be discussed by Dkane during the charged events. Some background testimony will be admissible to provide context to the Government’s case and may also help explain distributor’s or user’s quantity of the drugs. The Court found that testimony about types of controlled substances and how drugs are used is relevant.
However, the Court agreed with Jensen that Dkane’s testimony regarding harm to users or society generally, such as the unique overdose risk of fentanyl, is not relevant.
(3) Common Slang Terms
Jensen asserted that Dkane’s testimony regarding common slang terms and codes for controlled substances is unnecessary as none of the words at issue are uttered in this case. The Government acknowledged that this testimony is likely unnecessary in this case and it does not plan to introduce this testimony. The Court agreed that this testimony seems irrelevant in this case.
(4) Legal Opinions
Jensen asserted that certain opinions—such as whether fentanyl is a controlled substance—call for a legal conclusion that is for the Court and not the jury.
The Government responded that ” Dkane’s testimony that various drugs are controlled substances, while containing within it a legal conclusion, is obviously necessary as a predicate fact to explain why drug dealers do or not do certain things.” The Court agreed with the Government. Further, it appeared that Jensen is not contesting that the drugs at issue in this case are controlled substances under federal law as he has agreed to a jury instruction on to this effect.
(5) Testimony Regarding “In Furtherance Requirement”
Jensen asserted that admission of expert testimony on whether a firearm was possessed in furtherance of the charged drug trafficking would violate Rule 702.
However, the Government will not be relying solely on the expert testimony to establish that Defendant possessed a firearm in furtherance of a drug trafficking crime, but also intended to introduce evidence of the proximity, accessibility, and location of the firearms in relation to the locus of the drug activities.
2. Reliability
As a preliminary matter, the Court noted that Jensen did not challenge Dkane’s qualifications as an expert, nor did he dispute that Dkane has specialized knowledge on the topics of types of controlled substances or common characteristics of drug trafficking or drug traffickers and has based his opinions on that knowledge.
The Court found that the combined aspects of Dkane’s background, training and experience clearly meet the requirements of Federal Rule of Evidence 702 and qualify him to testify as an expert in the field of drug trafficking generally based upon his knowledge, skill, experience, training, and education.
Rule 403 Challenge
1. General Prejudice
Jensen asserted that “[g]eneral expert testimony regarding common methods and practices of drug dealers should be excluded because it gives rise to unfair prejudicial inferences that outweigh the limited probative value of the evidence.” While the Court is cognizant of the dangers raised by Jensen, the risk that unfair prejudice will actually materialize is not so high that it substantially outweighs the probative value of Dkane’s testimony.
2. Specific Prejudice
a. Comment on a Defendant’s Mental State
Jensen correctly asserted that a witness is not allowed to state an expert opinion or inference about whether the Defendant did or did not have a mental state or condition that constitutes an element of the crime charged.
Therefore, the Court granted Jensen’s motion but only as to excluding testimony by an expert as to whether the Defendant did or did not have a mental state or condition that constitutes an element of the crime charged.
b. Fentanyl addiction and deaths
Jensen argued that Dkane’s testimony concerning the addictive nature of fentanyl, the deaths it has caused, and the societal devastation resulting from its use did not prove the elements of the charged offense and created a substantial risk of prejudice.
The Court agreed that testimony regarding fentanyl statistics or death toll would be more prejudicial than probative and will exclude such testimony.
The Court will limit the Government to eliciting testimony on the dangers of fentanyl as related to drug trafficking practices and as explanatory information related to law enforcement’s handling of the investigation and the seized drugs.
c. Testimony regarding types of controlled substances
Jensen asserted that evidence about where the overwhelming majority of drugs trafficked in Washington are made, the fact that the drugs are usually smuggled into the United States through states other than Washington, and how they are transported to other localities are “wholly unconnected with the facts of this case.” The Court agreed that this type of evidence, while perhaps marginally relevant, is ultimately more prejudicial than probative.
Therefore, the Court granted Jensen’s request to exclude this type of testimony pursuant to Rule 403.
Held
The Court granted in part and denied in part the Defendant’s motion to exclude the testimony from Marco Dkane.
Key Takeaway:
An expert’s opinion may overlap with the jurors’ own experiences or cover matters that are within the average juror’s comprehension, so long as the expert uses some kind of specialized knowledge to place the litigated events into context. Therefore, Dkane’s testimony about the difference between distribution and user amounts of drugs and other details relevant to the distribution is relevant.
Case Details:
| Case Caption: | United States V. Jensen |
| Docket Number: | 2:24cr204 |
| Court Name: | United States District Court, Washington Western |
| Order Date: | August 28, 2025 |
