The Marin County Probation Department and Sheriff's Office identified three violations among DUI probationers during a joint compliance sweep on Friday, Sept. 18.

Officers targeted 35 people on supervised probation, completed 26 unannounced field contacts and administered 27 chemical tests, according to a county news release. The Sheriff's Office, which provides law enforcement services across unincorporated Marin, assisted in the operation. No one was arrested.

The three violations included possession of vehicle keys and failure to have a required ignition interlock device installed in a vehicle. One alcohol test came back positive. No drug-related violations were found.

Officers also conducted 28 searches and verified six ignition interlock devices as properly installed. Six of the 35 probationers identified for the operation were not contacted.

"The outcome of this operation reflects the importance of proactive supervision, clear expectations, and early intervention," Interim Chief Probation Officer Edward Randle said in the release. "Our role is to hold individuals accountable while providing the structure and support they need to make responsible decisions and successfully move forward."

The Sept. 18 sweep follows two other recent operations. A March 13 operation targeted 39 probationers, made 25 unannounced field contacts, found two violations and led to one arrest for a positive blood-alcohol concentration and failure to follow treatment directives. A Dec. 2, 2025, operation checked 50 individuals and found eight violations with no arrests. That December operation also involved the Marin County District Attorney's Office.

The checks include surprise home visits, vehicle searches for interlock devices, and breath and oral-swab tests for alcohol and drugs, according to county records.