St. Martinville, Louisiana - Louisiana State Police Troop I investigators are searching for an 18-wheeler driver who struck and killed a motorcyclist on Louisiana Highway 347 in the early morning hours of October 17, 2025.

Harvey Gauthier, 49, of St. Martinville, died at the scene of the crash near Lou Gauthier Road shortly after 5:00 a.m.

According to the preliminary investigation, Gauthier was riding a 2007 Honda off-road motorcycle southbound on LA Hwy 347 when the motorcycle suddenly braked and lost control. The motorcycle turned onto its side, and Gauthier was thrown from the vehicle, landing partially in the northbound lane.

An 18-wheeler traveling northbound on LA Hwy 347 then struck Gauthier as he lay in the roadway. The driver of the commercial vehicle did not stop and continued traveling north.

Gauthier sustained fatal injuries and was pronounced dead at the scene. Investigators collected a standard toxicology sample from Gauthier and submitted it for analysis, which is a routine procedure in fatal crashes.

The investigation remains active as troopers work to identify the 18-wheeler and its driver involved in the incident.

Louisiana State Police are requesting public assistance in locating the commercial vehicle. Anyone with information related to the crash is urged to contact Louisiana State Police Troop I at (337) 262-5880.

Tips can also be submitted anonymously through the Louisiana State Police online reporting system at File a Report or by calling the LSP Fusion Center Hotline at 1-800-434-8007.

At the time this was published, authorities had not released additional details about the investigation, including what caused Gauthier's motorcycle to brake abruptly or lose control.

All persons are presumed innocent until proven guilty.