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Press Release

Dubuque Man Pleads Guilty to Perjuring Himself Before a Federal Grand Jury

For Immediate Release
U.S. Attorney's Office, Northern District of Iowa

A Dubuque man pled guilty today in federal court in Cedar Rapids to perjuring himself before a federal grand jury in January 2017.


John Michael Gronen, 19, from Dubuque, Iowa, was convicted of the crime of making a false declaration before a grand jury. At the plea hearing, and in a plea agreement, Gronen admitted that he testified falsely, under oath, before a grand jury in the Northern District of Iowa on January 10, 2017. Specifically, Gronen falsely testified that he had never seen a particular sawed-off shotgun, when in truth he had seen another individual carrying the sawed-off shotgun in September 2016. Further, Gronen falsely testified that no one was using drugs at his house on September 22, 2016, when in truth he saw two people using cocaine and marijuana in his basement on that date.


Sentencing before United States District Court Judge Linda R. Reade will be set after a presentence report is prepared. Gronen was released on a personal recognizance bond, subject to a number of terms and conditions, pending sentencing. Gronen faces a possible maximum sentence of five years’ imprisonment, a $250,000 fine, a $100 special assessment, and three years of supervised release following any imprisonment.


The case is being prosecuted by Assistant United States Attorney Tim Vavricek and was investigated by the Dubuque Police Department. Court file information at

The case file number is 17-cr-31-LRR.


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Updated May 25, 2017

Firearms Offenses