A subpoena may be served by any person, but a peace officer must serve in his district any subpoena delivered to him for service, either on the part of The People or the defendant. Service of a subpoena is made by showing the original to the witness personally and delivering a copy thereof to him or sending it by mail to his last address, with return receipt. The person serving a subpoena must make a written return of the service, stating the time and place of service. In case where service is made by mail he must also include the return receipt.
Puerto Rico Legal Code