A sailor who hid below decks for seven days on the USS Shiloh, prompting the Navy to think he died after falling overboard, has been transferred to the brig at Marine Corps Air Station Miramar in San Diego, where he will be confined to await a possible court-martial, Navy Times reports.

Gas Turbine Systems Technician 3rd Class Peter Mims went missing on June 8, prompting a 50-hour search of 5,500 square miles of ocean near Okinawa by the U.S. and Japanese navies. He was found on June 15 hiding out in one of the engine rooms.

Mims was examined by medical staff and seen by investigators before being sent to the brig at Miramar.

“We do not know all the details and motivations behind this Sailor’s week-long disappearance,” Lt. Cmdr. Matt Knight of the U.S. Pacific Fleet public affairs office wrote in a statement to Action News Jax. “This matter remains under investigation, but early indications are that he had taken steps to avoid being found by other Sailors, who were actively attempting to locate him.”

The investigation is expected to continue through the summer, according to Navy Times.

“The Shiloh never stopped searching for their shipmate and their tenacity paid off,” Knight said. “Mims was found in the engineering spaces, where he turned himself in to his shipmates. We are thankful that he was found alive and will get him the support he needs at this time.”