SOMERSET — A Fall River man was arrested early Sunday morning after Somerset police allegedly found him in possession of over 100 grams of fentanyl and other drugs.

Lucas Souza, 28, of Fall River, was charged with trafficking fentanyl over 10 grams, possession of a class C drug, possession of a class B drug (two counts), operating under the influence of drugs and improper storage of a firearm.

At around 12:33 a.m., a police detective on patrol in the area of the Park and Ride on Slades Ferry Avenue saw a Dodge pickup truck backed into a space next to a trailer. The lone occupant of the truck, later identified as Souza, appeared to be ducking down to avoid being seen, according to a release from Somerset police.

When officers, including the Somerset Police Department's K-9 Unit, approached the vehicle they saw an empty firearm holster and what appeared to be drugs inside the truck, police said.

A search of Souza and his truck turned up 114 grams of fentanyl as well as lorazepam, buprenorphine and adderall.

Police also indicated Souza's speech was slurred and his eyes were bloodshot and watery.

Officers also seized ammunition from the scene, and through a subsequent investigation located and seized a handgun, police said.

Souza was taken into custody without incident and is being held pending his arraignment.

According to Somerset police, the investigation remains ongoing and they have not ruled out the possibility of additional charges.