Expert Witness Profiler

Tag: Machinegun

  • Firearms Expert’s Testimony Excluded Because of His Limited Experience with Machineguns

    Firearms Expert’s Testimony Excluded Because of His Limited Experience with Machineguns

    Defendant Chase Farmer was charged and convicted of multiple firearms offenses in a trial spanning April 29, 2025, to May 6, 2025. Specifically, Defendant was charged with importing, possessing, transporting, and failing to keep proper records for drop-in auto sears (“DIAS”) and Glock switches from Russia, which are machinegun conversion devices regulated as machineguns under the National Firearms Act (“NFA”).

    Four days before trial commenced, the Government filed a motion in limine seeking to exclude various witnesses that Defendant proposed.

    The Court granted the Government’s motion in part. However, the Court took under advisement the Government’s request to exclude Defendant’s proposed firearms expert, Tyler Hilliker. The Court explained that it had doubts that Hilliker met the qualifications for an expert witness.

    Firearms Expert Witness

    Tyler Hilliker founded Hilliker Arms in 2021, and for the following two years was engaged solely in instructing on safe firearms handling and concealed carry.

    He has also completed several courses pertaining to firearms.

    Get the full story on challenges to Tyler Hilliker’s expert opinions and testimony with an in-depth Challenge Study.

    Discussion by the Court

    The Court found that Hilliker’s experience with DIAS and Glock switches is derived solely from watching others work with them, mostly on video, and relatively few times. Moreover, Hilliker’s experience with machineguns in general is limited. He has only manufactured three machineguns: two AR-15s modified with traditionalstyle sears and an Uzi.          

    Moreover, Hilliker based his conclusions in his expert report on modifying an AR-15 with what he called a “traditional” auto sear—not a DIAS. Thus, there was no “fit” between Hilliker’s proffered testimony and the pertinent inquiry in this case, which involves DIAS and Glock switches specifically.

    Held

    The Court granted the government’s motion to preclude Tyler Hilliker as an expert witness.

    Key Takeaway:

    While Hilliker may be knowledgeable about firearms in general, it does
    not mean he is qualified to be an expert witness about converting firearms into machineguns via DIAS or Glock switch.

    Case Details:

    Case Caption: USA V. Farmer
    Docket Number: 2:22cr20678
    Court Name: United States District Court, Michigan Eastern
    Order Date: May 07, 2025
  • Firearms & Ballistics Expert’s Observations of Glock Firearms is Relevant

    Firearms & Ballistics Expert’s Observations of Glock Firearms is Relevant

    Defendant Osman Malik Sesay (the “Defendant”) is charged in a seven-count Third Superseding Indictment. Counts Three and Four alleged that, on April 29, 2021, the Defendant possessed a Glock 26, 9mm semiautomatic pistol (“Exhibit 008”) and approximately 18 rounds of 9mm ammunition in furtherance of a drug trafficking crime. Counts Six and Seven alleged that, on July 16, 2021, the Defendant possessed several other firearms.

    The Government will have to prove that Glock firearm identified as “Exhibit 001,” installed with the conversion device identified as “Exhibit 001A,” constitutes a “machinegun.”

    During discovery, the Defendant disclosed the rebuttal report of his firearms expert Brian Luettke. 

    Luettke will opine, inter alia, that Exhibit 001A “was crudely made[,] . . . is not dimensionally correct in size to function as a machinegun conversion device[,]” and, specifically, “does not fit correctly into the rear part of [Exhibit 001’s] slide.”

    Government filed a motion to exclude Luettke’s testimony as “based on an erroneous understanding” of the statutory definition of “machinegun” and “not based on any reliable methodology.”

    Firearms & Ballistics Expert Witness

    Brian Luettke has 22 years of experience as an Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) special agent, provided instruction to ATF agents on firearms, and served in multiple supervisory positions before retiring in 2020.

    Get the full story on challenges to Brian Luettke’s expert opinions and testimony with an in-depth Challenge Study.

    Discussion by the Court

    As such, the Court found that Luettke’s opinion that Exhibit 001A does not function as a machinegun conversion device is directly relevant to the offense charged in Count Six of the Third Superseding Indictment.

    Luettke determined that Exhibit 001A “is not dimensionally correct in size to function as a machinegun conversion device[,]” which tends to make it less probable that, when Exhibit 001 was possessed by Defendant, it satisfied the statutory definition of a “machinegun.” Specifically, if Luettke’s opinion is accepted, it would tend to make it less probable that Exhibit 001, with Exhibit 001A installed, “[was] designed to shoot, or [could] be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger.”

    Analysis

    The Court held that Luettke’s conclusions would assist the jury in deciding whether Exhibit 001, with Exhibit 001A installed, satisfies this portion of the statutory definition of “machinegun.”

    Luettke also test fired the separate Glock firearm identified as “Exhibit 008,” installed with a conversion device identified as “Exhibit 008A.”

    The Government argued that “the statutory definition does not require that the device fire reliably.” However, Luettke’s conclusions are not based solely on the inconsistent or unreliable automatic firing of Exhibit 001. They are also based Luettke’s own observations and measurements of Exhibits 001A and 008A.

    Therefore, Luettke’s opinion may assist the jury in determining, from the totality of the evidence, whether Exhibit 001, with Exhibit 001A installed, was “designed to shoot” or could be “readily restored to shoot” in the manner of a “machinegun” when the Defendant allegedly possessed them.

    The Government argued that Luettke failed to explain how his measurements supported his conclusion. The Court disagreed. Exhibit 001A was cracked and bowed when installed in Exhibit 001 at the time SA Eisenbise received the firearm, and she had to alter Exhibit 001A in order for the device to permit automatic firing of Exhibit 001. 

    Held

    The Court denied the Government’s motion to exclude the testimony of Brian Luettke.

    Key Takeaway:

    Luettke’s observations of both Glock firearms and both conversion devices demonstrated a technical connection between the size of a machinegun conversion device and its effectiveness as a machinegun conversion device for a given firearm.

    In sum, the Court found Luettke’s opinions to be relevant and based on reliable methods.

    Case Details:

    Case Caption: United States V. Sesay
    Docket Number: 1:21cr298
    Court Name: United States District Court, Maryland
    Order Date: April 18, 2025