Sheriff's Office

PR #:
Date Issued:
Sep 03, 2021 - 5:55AM

For Immediate Release

RSONU detectives arrest non-compliant sex offender thanks to Secret Witness tip
Please note: this is a regional press release

For media inquiries contact:
Sarah Johns
Washoe County Sheriff's Office
Office: 775-785-6235
Cell: 775-391-0407


James Timothy Mortensen, 58, was arrested by Regional Sex Offender Notification Unit (RSONU) detectives for being a non-compliant sex offender on September 1, 2021 thanks to a Secret Witness tip. Mortensen is a Tier III sex offender previously convicted in Vacaville, California for crimes against children.

RSONU detectives received information from the anonymous Secret Witness tipster that Mortensen was living in Panther Valley; however, Mortensen was not registered at that particular address. During the investigation detectives determined that Mortensen had been living at the residence for more than a month. Detectives made contact and arrested Mortensen for one felony count of being a sex offender who failed to update his address; and for one felony count for being a sex offender who failed his 90 day check-in.

The RSONU was formed in 1998 to be in compliance with federal law passed in 1997.  At that time Washoe County, the City of Sparks and the City of Reno all agreed there was a need for coordination in law enforcement in the tracking, monitoring, investigation, public notification, and the arrest and prosecution of non-compliant sex offenders.  The RSONU operates as a regional, multi-jurisdictional and collaborative entity to carry out the requirements of community notifications as set forth in Chapter 179D of the Nevada Revised Statutes.  The RSONU’s jurisdictional boundaries encompass all of Washoe County, including the Cities of Reno and Sparks.

Currently, there are about 1400 registered sex offenders in the Reno, Sparks and Washoe County area.  Each of the three investigators are assigned over 400 offenders to monitor.

The RSONU is open Monday through Friday, 7am to 5pm, excluding holidays, and can be reached at 775-325-6483.


The Washoe County Sheriff's Office is dedicated to preserving a safe and secure community with professionalism, respect, integrity and the highest commitment to equality. Sheriff Darin Balaam is the 27th person elected to serve as the Sheriff of Washoe County since the Office was created in 1861. The Washoe County Sheriff's Office strives to ensure public safety by building trust and creating partnerships within the diverse communities in which we serve. We will promote the dignity of all people supported by our words and actions through open communication while fostering an environment of professionalism, integrity and mutual respect.


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