According to the official website of the Massachusetts Executive Office of Public Safety and Security, a sex offender is defined as:
any person who resides, works or attends an institution of higher learning in the Commonwealth and who has been convicted of a sex offense, or who has been adjudicated as a youthful offender or as a delinquent juvenile by reason of a sex offense, or a person released from incarceration or parole or probation supervision or custody with the department of youth services for such a conviction or adjudication, or a person who has been adjudicated a sexually dangerous person or a person released from civil commitment on or after August 1, 1981.
Massachusetts has three levels of sex offenders.
Level One sex offender:
Where the Sex Offender Registry Board determines that the risk of reoffense by an offender is low and the degree of dangerousness posed to the public by that offender is not such that a public safety interest is served by public availability, the Board shall give that offender a Level 1 designation. Information on Level 1 offenders will not be available to the public. Neither the police nor the Board have authority to disseminate information to the general public identifying a Level 1 offender. Information identifying Level 1 offenders may only be given to the Department of Correction, any county correctional facility, the Department of Youth Services, the Department of Social Services, the Parole Board, the Department of Probation and the Department of Mental Health, all city and town police departments and the Federal Bureau of Investigation for law enforcement purposes.
Level Two sex offender:
Where the Board determines that the risk of reoffense is moderate and the degree of dangerousness posed to the public is such that a public safety interest is served by public availability of registration information, it shall give a level 2 designation to the sex offender.
The public can access information on Level Two offenders through local police departments and through the Sex Offender Registry Board.
Level Three sex offender:
Where the Board determines that the risk of reoffense is high and the degree of dangerousness posed to the public is such that a substantial public safety interest is served by active dissemination, it shall give a level 3 designation to the sex offender.
Just as with Level Two offenders, information on Level Three offenders is available from police and the Sex Offender Registry Board.