"In Petty Officer Matthews' case, we certainly empathize with his situation, but we certainly do not condone his actions," Maestas said.
Search and rescue crews scoured more than 10,000 square miles looking for Matthews. Honolulu firefighters sent a helicopter and rescue teams to searches the rugged coastline and sand dunes near Kaena Point.
Maestas couldn't discuss what Matthews was doing while he was missing, saying that's part of the investigation.
Maestas said he didn't know if Matthews has an attorney. He is entitled to representation by a lawyer from the Navy's judge advocate general corps if he wishes.
Matthews joined the Coast Guard in 1997. He's been stationed at Air Station Barbers Point on Oahu for five years.
The decision to charge Matthews was made by Capt. Timothy Gilbride, the station's commanding officer.