Troopers Stop Motorcycle Rider for Speeding, Discover Signs of Drug Use

Missoula, MT (KGVO-AM News) - At approximately 5:15 p.m. on March 24th, 2025, a Montana Highway Patrol trooper and a field training officer were patrolling eastbound along Secondary 474. The speed limit is 55 miles per hour in that area. They observed a motorcycle traveling westbound at a speed of 70 miles per hour.  

The troopers initiated a stop of the motorcycle. When asked for his license, the driver indicated that he did not have his license on him, but was licensed to drive and held a motorcycle endorsement. The driver, 55-year-old William Mahlert, provided his name and a date of birth. 

A trooper observed that Mahlert’s speech was slurred, his pupils were constricted, and his face was constantly twitching. The trooper ran a driver’s license query with the name and date of birth provided. The photo returned appeared to be consistent with the driver, however, the driver present appeared gaunt from weight loss. Mahlert was also missing many front teeth. The return indicated that Mahlert did not have a driver’s license.  

Mahlert was asked about methamphetamine use, which he denied having ever used. The trooper administered standardized field sobriety tests. He observed 7 out of 18 clues of impairment. The other trooper then performed tests related to possible drug impairment and observed Mahlert’s eyes jerking abnormally. 

Mahlert was read a preliminary alcohol screening advisory and agreed to provide a breath sample, which showed that alcohol was not present. He was then read an implied consent advisory and refused to provide a blood sample.  

READ MORE: Missoula News – Crime Reports 

During a search incident to arrest, a trooper found suspected crystal methamphetamine, a suspected meth pipe, and a loaded marijuana vape device on Mahlert’s person. According to court documents, the methamphetamine related items have been sent to the state crime lab for further analysis, which is currently pending. 

Mahlert was transported to the Missoula County Detention Center. He is currently being charged with felony criminal possession of dangerous drugs, DUI first offense, and driving without a valid driver’s license.  

The information in this article was obtained from sources that are publicly viewable.