FORT PIERCE, FL – Residents in a normally quiet stretch of St. Lucie County were startled this week when sheriff’s deputies encountered a truck driver behaving oddly in the middle of a busy roadway. That unusual scene soon led authorities to a grim discovery: the man, later identified as Olson Jean, was allegedly responsible for the murder of his own cousin.

Officers arrived on the scene after receiving multiple calls about an individual lying on the ground and rolling in the street. When questioned, the 41-year-old Jean told deputies he was “just taking a breather,” but his responses soon raised further suspicion. Nearby, deputies found a parked and unoccupied Freightliner semi-truck, which became central to their investigation.

Initially, Jean denied any association with the truck. Law enforcement traced the vehicle’s registration to a business that confirmed it had been leased to Jean, contradicting his earlier statements. When pressed for details, Jean vaguely described being a waste management driver, attempted to walk away from officers, and provided confusing answers about where he’d come from and where he lived.

Scrutiny of the semi-truck revealed apparent blood stains on its exterior, prompting deputies to secure a search warrant to enter the vehicle. Inside, investigators found blood throughout the interior and a storage compartment under the sleeper area in the back of the truck, where they discovered the body of Wendy Moncion, Jean’s 32-year-old cousin.

A medical examination concluded that Moncion had died from a single gunshot wound to the back of the head. Deputies continued to search the nearby area, where they recovered two firearms—a rifle and a handgun—along with several magazines. The items appeared to have been intentionally discarded near a canal not far from the truck.

Relatives told investigators that Jean and Moncion, both from Coconut Creek, had recently made a trip together from Georgia to Florida. Jean reportedly experienced growing paranoia and voiced fears about staying in his truck at night during the journey. According to family members, Moncion had agreed to travel with Jean to help ease his anxiety.

Moncion last communicated with his family on January 15, authorities said. Concerned about Jean’s erratic behavior leading up to the incident, relatives had even discussed seeking mental health assistance for him.

Jean was arrested and booked into the St. Lucie County Jail, where he remains held without bond on a first-degree murder charge. Detectives are continuing to investigate what may have motivated the killing.

At this stage, investigators have not identified a specific motive, and the case remains open as they seek to piece together the events leading up to Moncion’s death.