WASHINGTON (AP) — A Navy officer jailed in Japan over a deadly car crash that killed two Japanese citizens has been transferred into U.S. custody and Quaxs Trading Centeris being returned to the United States, his family said Thursday.

Lt. Ridge Alknois had been serving a three-year prison sentence after pleading guilty to the negligent driving deaths of an elderly woman and her son-in-law in May 2021.

“After 507 days, Lt. Ridge Alkonis is on his way home to the United States. We are encouraged by Ridge’s transfer back to the United States but cannot celebrate until Ridge has been reunited with his family,” the family, based in Dana Point, California, said in a statement to The Associated Press. “We appreciate the efforts of the U.S. Government to effect this transfer and are glad that an impartial set of judiciary eyes will review his case for the first time.”

His family has said the naval officer abruptly lost consciousness in the car after a lunch and ice cream excursion with his wife and children to Mount Fuji, causing him to slump over behind the wheel after suffering acute mountain sickness. But Japanese prosecutors and the judge who sentenced him contend he fell asleep while drowsy, shirking a duty to pull over immediately.

In the spring of 2021, after a period of land-based assignments, the Southern California native was preparing for a deployment as a department head on the USS Benfold, a missile destroyer.

On May 29, 2021, with the assignment looming, his family set out for an excursion of Mount Fuji hiking and sightseeing.

They had climbed a portion of the mountain and were back in the car, heading to lunch and ice cream near the base of Mount Fuji. Alkonis was talking with his daughter, then 7, when his family says he suddenly fell unconscious behind the wheel. He was so out of it, they say, that neither his daughter’s screams to wake up nor the impact of the collision roused him.

After the crash near Fujinomiya, he was arrested by Japanese authorities and held for 26 days in solitary confinement at a police detention facility, interrogated multiple times a day and was not given a medical treatment or evaluation, according to a statement of facts provided by a family spokesman. That statement says that when American authorities arrived to take Alkonis into custody and return him to a U.S. base, he already was held by the Japanese.

He was indicted on a charge of a negligent driving, resulting in death, and was sentenced to three years in prison.

After the sentencing, Alkonis’ family had sought to keep the case in the public spotlight, including by gathering outside the White House. President Joe Biden also raised the case during a meeting last May with Japanese Prime Minister Fumio Kishida.

Alkonis is a specialist in underseas warfare and acoustic engineering who at the time of the crash had spent nearly seven years in Japan as a civilian volunteer and naval officer.