New York: A 14-year-old boy was arrested on a second-degree murder charge Friday after police say he fired a gun inside a New York City bus in a street gang dispute, killing a bystander who was speaking on his cellphone.

The victim, Angel Rojas, 39, wasn’t the target in the Thursday night shooting, Police Commissioner William Bratton told reporters. Rojas died from a gunshot wound to the back of the head.

Investigators suspect the shooting stemmed from a dispute between two gangs that had been taunting each other on social media. Police had not found the target.

The suspect boarded the bus in Brooklyn with two other people, police said. They were sitting in the back of the bus when the target boarded at another stop, they said.

The gunman fired an initial shot that hit Rojas, police said. As other passengers fled the bus, the suspect exited a front door and fired five more shots at the target as he ran away, they said.

Police officers on a foot patrol grabbed the suspect and recovered a six-shot revolver that was empty, police said.

Relatives say Rojas came to the United States four years ago from the Dominican Republic with his wife and two children.