Watertown SD News: Jeffrey Koistinen Defense Seeks to Suppress Post-Arrest Statements Before September Federal Trial

Northeast Radio SD News – Watertown, SD - As the September trial date approaches for Jeffrey Allen Koistinen, his defense team has launched a new legal challenge regarding the events of his August 2022 arrest.

On July 28, 2026, Koistinen’s defense attorney filed a formal motion to suppress the defendant’s post-arrest statements, adding a new layer to the ongoing pre-trial disputes over evidence. Koistinen is facing federal charges that include child pornography and coercion, with a jury trial currently scheduled for September 22, 2026.

The July 28 Suppression Motion

The newly filed “Defendant’s Motion to Suppress Post-Arrest Statements and Fruits” seeks to exclude statements Koistinen made to law enforcement on the evening of August 17, 2022. The defense argues that Koistinen’s Fifth and Sixth Amendment rights were violated because he was subjected to a custodial interrogation without being advised of his Miranda rights.

According to the court filings and attached body-worn camera transcripts:

·         The Stop: Koistinen and his wife were pulled over by Tucson Police Department Officer Phillip Hengsteler shortly after leaving their Marana home.

·         Right to Counsel: During the initial encounter, Koistinen told the officer, “We were told by our attorney, don’t say anything to you guys.”

·         Custodial Status: Koistinen was subsequently handcuffed, told he was under arrest, and placed in the back of a Marana Police Department patrol vehicle.

·         The Interrogation: The defense alleges that while Koistinen was handcuffed in the vehicle, Officer Hengsteler approached him and asked about the location of his phone without ever administering a Miranda warning.

The defense argues that because Koistinen was in custody, had invoked his right to counsel, and was asked a question likely to elicit an incriminating response, any statements made—and any evidence resulting from those statements—must be suppressed.

Connecting to the “Blue iPhone” Dispute

This new filing appears closely tied to the primary cause of the trial’s ten previous delays: the legal battle over a seized “blue iPhone.”

Earlier this year, a Magistrate Judge issued a Report and Recommendation advising the District Court to deny earlier defense motions aimed at suppressing data from the device. While federal prosecutors successfully argued that the phone’s seizure was lawful under the “automobile exception,” the defense’s new tactic focuses specifically on suppressing the statements Koistinen made regarding the phone’s location.

The defense is requesting that the Court exclude the statements entirely or, at a minimum, hold an evidentiary hearing to determine if Miranda violations occurred.

Upcoming Schedule

The District Court will now need to weigh this new motion alongside the pending final ruling on the Magistrate’s previous recommendations. Koistinen remains in federal custody as the pre-trial deadlines approach.

Key Upcoming Dates:

·         Plea Deadline: September 04, 2026, by 3:00 p.m.

·         Jury Trial: September 22, 2026, at 9:30 a.m.

Note: Koistinen has pleaded not guilty to all counts. All defendants are presumed innocent until and unless proven guilty in a court of law.

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