As the postal worker and Acevedo were fighting over the package, Boston Police arrived and arrested Acevedo, charging him with robbery and aggravated assault on the postal worker.
The postal worker was taken to a hospital for injuries he received during the fight.
The next day, federal agents said they opened the package after obtaining a search warrant and found approximately 1.390 kilograms of cocaine.
Acevedo appeared in federal court in South Boston on Tuesday. The judge ordered him held pending a probable cause and detention hearing set for Thursday.
The charge of assaulting a federal postal worker provides for a sentence of up to 20 years in prison and up to three years of supervised release. The charge of distribution of cocaine provides for a minimum mandatory sentence of five years and up to 40 years in prison, four years to a lifetime of supervised release and a fine of up to $5 million.