Cops busted a teen who argued with a Bronx Dunkin’ Donuts customer moments before he was shot dead last month, authorities said. 

Santiana Rodriguez, 18, was arrested Monday and charged with murder for her role in the broad-daylight March 18 slaying of Jamaican immigrant Stephaun Stewart, 24, outside the coffee shop on Holland Avenue near East 212th Street, cops said. 

Police could not confirm Tuesday morning who pulled the trigger. 

Authorities confirmed that Stewart and a friend got into an argument with Rodriguez after she cut the line, cops said.

“She tells them to back off because they probably have COVID,” a police source said. 

The victim and his friend then left the shop, but the woman followed them out, the source said.

The woman can be seen on surveillance video making a call.

She then met up with a man believed to be between 17 and 25 years old and had another confrontation with Stewart, police said. Police sources said the man was her boyfriend.

During that clash, the man and woman “mentioned something about getting a gun” before the man went into a building, according to the source. 

Stewart and his friend then split up and went in different directions. Police believe Stewart was shot to death sometime after that.

The victim, who arrived in the US in December 2021, was blasted in the torso and rushed to Jamaica Medical Center, where he was pronounced dead.

Stewart’s aunt, who did not give her name, said he was always “the one to carry the peace.”

“Most of the family is devastated. He’s just that person,” she said. “I don’t know why somebody would do this to him, over a simple issue. That didn’t call for somebody losing life.”