Former Olmsted deputy sentenced to 19.5 years in federal hearing
(ABC 6 News) – A former Olmsted County Sheriff’s deputy accused of child sex crimes was sentenced to 235 months, or about 19.5 years in federal court Jan. 15.
Mathew Adamson pleaded guilty to one federal charge of producing or attempting to produce child pornography.
Adamson is still listed as an inmate at the Sherburne County Jail as of Thursday, Jan. 16.
Adamson’s attorney, Lee Johnson, said 235 months was on the ‘low end’ of the 235-to-293-month agreement specified in Johnson’s plea deal.
He said there were no plans to appeal at present.
Adamson was also sentenced to 20 years on probation after release.
Adamson, a former Olmsted County ADC staffer, was originally charged with multiple sex crimes in November and December of 2023: including child solicitation, possession of child pornography, and interference with privacy after allegedly saving explicit photos of detainees at the jail.
He is scheduled to appear for pretrial hearings in his Olmsted County cases March 19, followed by jury trials beginning April 7.
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(ABC 6 News) – A former Olmsted County Sheriff’s deputy pleaded guilty to one of three production of child pornography charges in federal court Thursday, Aug. 29.
Mathew Adamson faces a mandatory minimum 15-year sentence for the single charge of producing or attempting to produce child pornography.
However, court documents filed Thursday evening state that Adamson can expect a 19-to-24-year sentence based on the severity of his particular case.
The federal maximum for the charge is 365 months, or just over 30 years, according to court documents.
However, Adamson’s plea agreement caps his sentence at 293 months.
Adamson’s sentencing had not been scheduled Thursday evening.
RELATED: Former Olmsted County deputy schedules federal change-of-plea hearing – ABC 6 News – kaaltv.com
Federal plea deal
Adamson originally faced five federal charges related to producing CSAM, or Child Sexual Abuse Materials, featuring 12-to-13-year-old girls: three charges of production or attempted production of child pornography, one count of possession of child pornography, and a count of coercion and enticement.
Adamson pleaded guilty to the third count of production of child pornography in exchange for the dismissal of the other federal charges.
In Adamson’s plea agreement, he admitted to contacting a 12-year-old (Minor C) over the app Whisper, while pretending to be a “Nate” and used that persona to convince the child to send him lewd photos.
On July 10, 2023, Adamson coerced the child to meet with him for sexual activity, which he recorded, according to the plea agreement.
Adamson’s plea agreement also indicated that he had used the Whisper app to solicit multiple minors to engage in sex acts, and had also installed hidden cameras to record minors undressing and showering.
While the mandatory minimum sentence for production or attempted production of child pornography is 15 years in Minnesota, Adamson’s baseline was raised because Minor C was 12 years old, and he obscured his own identity to solicit the child.

Olmsted County child sex crime cases
Adamson, a former deputy working at the Olmsted County Adult Detention Center, was originally charged with multiple child sex crimes locally in November and December of 2023.
Altogether, Adamson faces 11 charges in Olmsted County, including child solicitation, possession of child pornography, and interference with privacy after allegedly saving explicit photos of detainees at the jail.
As of Thursday, Aug. 29, new hearings had not been set in Olmsted County.