A Modesto man involved in a fentanyl and firearm trafficking ring operating in Stanislaus County was sentenced Monday to more than 11 years in federal prison, U.S. Attorney Eric Grant said.

Oleg Arreola, 28, was sentenced by U.S. District Judge Troy L. Nunley to 11 years and three months in prison after pleading guilty to being a felon in possession of a firearm in connection with a broader drug and gun trafficking conspiracy uncovered during a multi‑agency investigation known as Operation Blue Death.

According to court documents, the investigation targeted a network of individuals distributing fentanyl pills and firearms in Stanislaus County between September 2022 and June 2023. Seven people were charged in a 17‑count indictment.

Prosecutors said that in March and April 2023, co‑defendant Arturo Madrid sold several firearms and thousands of fentanyl pills, including a sale on April 21, 2023, involving 6,000 pills and a Draco PAK 9 rifle.

On June 13, 2023, Arreola, Madrid, Andrew Rodriguez, and Enrique DeLeon arrived at a pre‑arranged location to purchase 50,000 fentanyl pills, according to the indictment. Officers arrested the four shortly after they arrived. Arreola had an AK‑style Draco rifle at his feet when he was taken into custody. DeLeon had about 30,000 fentanyl pills inside a briefcase in his vehicle.

Several defendants have already been sentenced. Madrid, 29, of Modesto, pleaded guilty to distributing fentanyl and possessing a firearm as a felon and received 11 years and three months in prison in November 2025. DeLeon, 28, of Salida, pleaded guilty to possessing 30,000 fentanyl pills with intent to distribute and was sentenced to the same term in April 2025.

Two Turlock residents, Ebony Lambert, 48, and Donnell Mays, 50, also pleaded guilty to distributing fentanyl. Lambert was sentenced to two years in prison in August 2025. Mays is scheduled to be sentenced July 13, 2026, and faces a mandatory minimum of 10 years and up to life in prison.

Two remaining defendants — Andrew Madrid and Andrew Rodriguez — are scheduled for trial on Sept. 22, 2026. Madrid is charged with conspiracy to distribute fentanyl and distributing fentanyl. Rodriguez faces conspiracy and distribution charges, two counts of being a felon in possession of a firearm, and a charge of using or carrying a firearm during a drug trafficking offense. If convicted, both face a mandatory minimum of 10 years and a maximum of life in prison. Rodriguez faces an additional mandatory minimum of five years for the firearm‑related charge.

The case was investigated by the Stanislaus County Sheriff’s Office and the FBI. Assistant U.S. Attorney Cody S. Chapple is prosecuting.

Operation Blue Death is part of the Homeland Security Task Force initiative created under Executive Order 14159, which focuses on dismantling criminal cartels, transnational criminal organizations, and trafficking networks operating in the United States and abroad.