Prosecutors in Japan have filed formal charges against a US marine suspected of murdering and robbing a woman while stationed on the country’s island of Okinawa, according to Japanese media.

Devin Jacob Ballard, a 20-year-old lance corporal assigned to Marine Corps Air Station Futenma in Okinawa, is charged with fatally strangling Anna Yagi, 39, at a hotel in the city and stealing from her a backpack containing a wallet, the public broadcaster NHK reported.

Ballard had initially been arrested in Yagi’s killing on 4 October, about a day after she was found dead in Naha, Okinawa’s capital. Prosecutors indicted him in the case on Sunday, and he has reportedly denied the charges.

NHK and other Japanese media outlets had previously reported that Ballard was arrested after surveillance camera footage from near the scene of Yagi’s killing showed a man entering a room with a woman and later leaving the scene with her belongings.

Ballard evidently matched the description of the suspect seen in the footage, was confronted and agreed to accompany investigators voluntarily to a local police station when he was arrested, Japanese media reported.

Yagi’s killing prompted protests in Okinawa and the Japanese capital of Tokyo, with political leaders publicly condemning her killing. It also triggered a curfew and alcohol ban for US military members stationed in Okinawa, where most of the 54,000 US troops in Japan are based.

Crimes committed by US troops in Japan – including rape, assault, hit-and-run and drunk-driving – have long strained relations between the countries, which are close military allies.

A Japanese court in June 2025 sentenced US marine Jamel Clayton, then 22, to seven years in prison after he was convicted of choking and sexually assaulting a woman in her 20s.

In 2017, a former US marine and civilian military base worker named Kenneth Shinzato was sentenced to life in prison for the rape and murder of a local Okinawa woman.

US military forces in Japan that same year banned all personnel from consuming alcohol after an intoxicated US marine crashed his vehicle into a mini-truck, killing a local driver, age 61.

The Yomiuri Shimbun newspaper reported that about 6,000 US military personnel have been arrested since the US returned Okinawa to Japan after the second world war in 1972.

There were 80 such arrests in 2024, constituting a 20-year high.

After Ballard’s arrest, Shinjiro Koizumi, Japan’s defense minister, said: “Incidents and accidents involving US military personnel cause great anxiety among the local community and must not be allowed to happen.”

Reuters and Agence France-Presse contributed reporting