After disappearing three months ago Petty Officer Russell Matthews suddenly showed up at his North Shore Oahu home Sunday night. An investigation is underway to figure out where he's been and what he's been doing. We do know Matthews, 36, was being investigated for illegal drug use when he disappeared. Early last October his car and slippers were found at Kaena Point. His hat was in the water. The Coast Guard searched 10,000 square miles over two days but there was no sign of him. Three months later Honolulu Police say he appeared at his wife's home on the North Shore Sunday night. He was incoherent and officers took him to Castle Medical Center in Kailua. The next morning he called his Coast Guard commanders and told them he was in fact alive.