Massachusetts General Laws Part IV. Crimes, Punishments and Proceedings in Criminal Cases (Ch. 263-280) Ch. 276, § 10

The aldermen or the selectmen, if in their opinion the public good so requires, may offer a suitable reward of not more than five hundred dollars in any one case, to be paid by the town to any person who, in consequence of such offer, detects or secures a person who has committed a felony in such place, either before or after he has been charged therewith, and such reward shall be paid by the treasurer upon the warrant of the aldermen or selectmen. If more than one claimant applies for the payment of such reward, the aldermen or selectmen shall determine to whom it shall be paid, and if to more than one person, in what proportion to each, and their determination shall be final.

The aldermen or the selectmen may offer a reward of five hundred dollars for information leading to the arrest and conviction of a person making or circulating or causing to be made or circulated a false alarm of fire.

In a city, the mayor, with the approval of the city council or, in a town, the selectmen, may offer a reward of not more than five thousand dollars, in any one case, to be paid by the town or city to any person who, in consequence of such offer, detects or secures the arrest and conviction of a person who assassinates or attempts to assassinate a police officer employed by such city or town. Such reward shall be paid by the treasurer upon the warrant of the mayor or selectmen. If more than one claimant applies for the payment of such reward, the mayor or selectmen shall determine to whom it shall be paid, and if to more than one person, in what proportion to each, and said determination shall be final.