Marijuana grow case concludes in Burnett County court; Olson Sr. receives five-year deferred judgment
CRIME
SIREN — The Burnett County marijuana grow-operation case that began with a June search of a Siren Township property reached its final resolution on Friday, when Matthew Olson Sr. pleaded guilty to manufacturing THC and received a five-year deferred judgment — an agreement under which no conviction is entered against him unless he violates its terms.
Olson Sr., 51, of Siren, pleaded guilty in Burnett County Circuit Court case 2026CF000089 under an amended information filed October 12 charging him with manufacturing and delivering THC. The charge alleged that on or about June 25, 2026, in Burnett County, he manufactured THC in an amount of 2,500 to 10,000 grams, or more than 50 but not more than 200 plants. The remaining counts were dismissed and read in. Judge Melissia Mogen accepted the plea and the parties' joint recommendation of a five-year deferred judgment, with conditions including a drug and alcohol assessment and any recommended treatment, and no further crimes.
The distinction matters: in court, Judge Mogen first stated that a judgment of conviction would be entered, then corrected herself on the record. “The judgment is not entered,” she said. If Olson violates the agreement, prosecutors can ask the court to enter judgment on his guilty plea; the charge as read in court carried a maximum of a $25,000 fine, 12½ years in prison, or both. Of the $5,000 bond Olson posted, the court directed $150 to the district attorney's office and the assessment fee to be paid from bond, and will hold $750 of the bond for the five-year term, with the rest refunded.
The deferred agreement grew out of a problem with the search itself. Prosecutors told the court the State agreed to the deal after reviewing body camera footage, the search warrant and the law, concluding that a defense challenge to the warrant could succeed at least in part. Defense counsel said the warrant was written for Nicholas Contreras — Olson's nephew — who did not live at the residence. Olson told the court the marijuana was for personal use. His attorney said the outdoor grow was essentially finished — the plants had been mowed over and kept growing back — with a quantity of dried marijuana stored in a shed. Prosecutors noted Olson's prior record includes a 2015 criminal trespass to dwelling case.
Olson Sr.'s resolution was the last of the three cases arising from the investigation. According to DrydenWire's reporting of court records, Matthew Olson Jr., 30, of Siren, pleaded no contest and was sentenced on September 28, 2026, with a remaining charge dismissed as part of his plea agreement. Nicholas Contreras, 31, of Webster, pleaded guilty to a felony charge of delivering THC stemming from two controlled buys at a Siren bar and was sentenced in September 2026, according to the same reporting. Contreras is still facing drug-related charges in a separate Polk County court case; those charges are allegations, and he is presumed innocent in that case unless and until he is proven guilty.
DrydenWire reported that the June 2026 search of the Siren Township property found large quantities of marijuana, more than 50 growing plants, drug paraphernalia and multiple firearms.