Taunton police said surveillance video shows the clerk attempted to stop Davila from stealing a bottled drink from the beverage cooler. When the clerk put his arm across the cooler door, preventing Davila from opening it, Davila allegedly bit the clerk's arm and then his face.
Police said Davila was known to the clerk and had allegedly stolen from the store before.
While one witness prevented Davila from leaving the store, another person called 911 and tended to the clerk's wounds.
"The actions of the suspect represent an attack of an innocent worker just doing his job and trying to prevent the theft of merchandise from his place of employment," Police Chief Ed Walsh said. "I would like to commend the good Samaritans who were in the store at the time and helped the victim while preventing this dangerous suspect from escaping and possibly harming others."
Davila is expected to be arraigned at Taunton District Court later on Tuesday.