Transit police arrest Boston man accused of allegedly threatening another rider for wearing a mask

MBTA transit police officers arrested a Boston man Monday, after they say he allegedly used a knife to threaten another man because he was wearing a mask on a Red Line train.

Rafael Perez-Medina, 33, of Boston was taken into custody and charged with assault by means of a dangerous weapon, according to a statement from police.

Around 9 a.m. Monday, police said they responded to a call about an armed assault at the Downtown Crossing Red Line platform.

When they arrived, police found a 28-year-old man who told them he was threatened on a Red Line train by a man with a knife, according to the statement.

Police did not identify the victim. According to authorities, the incident started with a man, who police later identified as Perez-Medina, insulting the victim, saying things like “you look like a duck” with that mask on.

According to the statement, the two argued briefly about the mask, then Perez-Medina brandished a knife and said, “I’m in the Army. I’ll kill you.”

The 28-year-old, fearful for his safety, immediately exited the train and contacted police, according to the statement.

Police said the victim provided a detailed description of the man who threatened him, which led officers to Perez-Medina, who was arrested at Temple Place.

According to the statement, the victim positively identified Perez-Medina as the man who threatened him with a knife.