Section 94. Constables may serve the writs and processes described in section ninety-two and warrants and processes in criminal cases, although their town, parish, religious society or district is a party or interested. They shall have the powers of sheriffs to require aid in the execution of their duties. They shall take due notice of and prosecute all violations of law respecting the observance of the Lord’s day, profane swearing and gaming. They shall serve all warrants and other processes directed to them by the selectmen of their town for notifying town meetings or for other purposes. They may serve by copy, attested by them, demands, notices and citations, and their returns of service thereof shall be prima facie evidence; but this provision shall not exclude the service thereof by other persons.