MBTA transit police arrested a Level 2 sex offender Monday after the man allegedly tried to enter Ruggles station without paying a fare.
Transit Police said Willie Butler, 53, of Boston tried to evade paying a fare by following, or “piggybacking,’’ behind a paying patron at about 5:45 p.m. Monday.
As officers issued Butler a citation, they discovered his sex offender status. The officers also discovered that he had a warrant for his arrest issued by Stoughton District Court for failing to register as a sex offender.
Butler was arrested and taken into custody.
According to MBTA transit police spokesman Richard Sullivan, people arrested for minor infractions on the T are often wanted for more serious crimes.
“We believe that by enforcing the crimes at entry points of T stations, it will prevent larger crimes on the system,’’ Sullivan told Boston.com.