On November 4, 2019 at approximately 6:40PM members of the Transit Police Crime Suppression Team were on patrol at the MBTA's Park Street Station Red Line. While there they had their attention drawn to a male, later identified as Robert O'Brien, 49, of Arlington. O'Brien fare evaded by "piggybacking" in behind a paying patron. Officers approached O'Brien for the purpose of issuing a citation and subsequently discovered O'Brien had several warrants in existence for his arrest issued from Cambridge District Court for Arson, Breaking & Entering in the Night Time, Disorderly Conduct and Motor Vehicle violations. O'Brien was placed into custody and transported to TPD HQ for the arrest booking process.