San Antonio police say the shooting happened Sunday night at an apartment.
Philip Pavelko was charged Monday. No information was immediately available on an attorney for the Iraq war veteran, who was freed Tuesday after posting $30,000 bail.
Pavelko has said the shooting of his buddy was an accident.
The Marine Corps Air Station Miramar says the victim was Aaron Talley of Clarissa, Minn. Talley was a corrections specialist at the Naval Consolidated Brig assigned to the headquarters squadron at Miramar, Calif.
Police say Pavelko told investigators that the two men were joking around after dinner and had no idea that the shotgun was loaded.
