Sometimes, yes, many times a family member may call EMS to hand them the DNR, this ensures proper procedures are followed when dealing with the body, less mess, and a quicker certification of death. It may also be important in situations where the person is influencial or rich and ensures you cannot be accused of foul play.

No, DNRs have certain things that make them official, signatures and notarized markings. Usually one person will begin life saving measures while the ither verifies the DNR. EMS never work alone.