The return shall set forth, fully and explicitly, whether the defendant has or has not the party in his power or custody or under his restraint and, if he has, the authority and true cause of the confinement or restraint.
If a party is detained by virtue of any writ, warrant or other written authority, a copy thereof shall be annexed to the return.
If the party, upon whom the writ shall have been served, shall have had the party in his power or custody or under his restraint, but shall have transferred such custody or restraint to another, the return shall set forth fully the facts relating thereto.
The return shall be verified unless the same is made by a public officer in his official capacity.