A California trucker who was promised $6,000 to transport about $14 million worth of fentanyl across the country to Massachusetts has been sentenced to 3 ½ years in prison.

Nelson A. Garcia Martinez, 40, apologized to a judge at Wednesday’s sentencing in federal court in Worcester, saying he did not know that the 15 kilograms (33 pounds) he was transporting were fentanyl, The Telegram & Gazette reported.

Garcia Martinez pleaded guilty to drug charges in April. He was arrested in November 2018 at a Sturbridge truck stop. Authorities had been tracking him after his cellphone number was found during a drug bust in Methuen the previous month.

His attorney, Noah J. Kilroy, said his client is a father of five with no prior criminal history who was on his first run as a drug mule. Garcia Martinez, a native of El Salvador who is in the U.S. illegally, also faces deportation upon completion of his sentence.

Kilroy asked for a three-year sentence. Prosecutors asked for nearly four years.