The U.S. military in Japan has been more aggressive in charging and tracking deserters since a fugitive sailor stabbed a taxi driver to death last year, military legal staff and investigators said.

Since then, a dozen servicemembers have been charged with desertion and five remain at large, according to figures supplied by U.S. Forces Japan, Japanese police and local bases.

The Navy began a crackdown about a month after Seaman Olatunbosun Ugbogu, who was sentenced to life in prison last month, murdered a cab driver near Yokosuka Naval Base in March 2008.

Commands have pushed to issue desertion charges earlier — within hours or days compared to the month of absence that can trigger a desertion charge under military law. The Naval Criminal Investigative Service, which in the past worked such cases by request only, has launched investigations of all U.S. Navy desertions on the mainland.

“These days, when somebody goes missing for any significant period of time in Japan, they are very quickly declared a deserter,” said Lt. Jonathan Flynn, the staff judge advocate general for Yokosuka Naval Base. “Within a couple of days at the most — very often it is within hours — we turn around the various [desertion charge] forms.”

Desertion is a more serious crime — carrying a penalty of up to five years in prison and dishonorable discharge — compared to the similar charge of unauthorized absence, which carries a maximum prison term of 18 months.

To charge desertion, a command must determine a servicemember has no intention of returning to the military. Charges are routinely filed if a servicemember does not turn up after 30 days, but commands can decide to charge much earlier if they feel there is enough evidence.

Decisions could hinge on evidence such as whether the servicemembers took all their clothes and money when they disappeared, legal officials at Yokosuka and Sasebo Naval Base said.

“We are very forward-leaning in declaring it a desertion case,” said Lt. Josh Stutts, the staff judge advocate general in Sasebo.

Over the past year, 12 servicemembers were charged with desertion and five remain at large among about 48,000 servicemembers stationed in the country, the U.S. and Japan reported.

The cases originated from three areas. Yokosuka charged seven troops with desertion, the highest number, and two are still missing. Sasebo had three desertions with two still missing, and Okinawa had two with one still at large.

“It is easier to find some people more than others,” said Gregory Ford, supervisory special agent at the NCIS Far East field office. “Sometimes it will be a week, and sometimes it will be a month. Japan is a big country.”

The agency, reacting to concern among the Japanese, changed its policy and began investigating all desertions about a month after the Ugbogu murder, according to Ford.

“I would expect that because we are looking at all of them now, we will be able to solve more,” said Ford, who declined to discuss specifics of ongoing investigations.

Two missing deserters who were stationed at Sasebo are believed to be in the United States and the Philippines, according to officials at that base.

Officials at Yokosuka said one deserter from the base was arrested in the U.S. in the past year but would not comment on the believed whereabouts of two deserters who are still missing.

Marine Corps officials in Okinawa did not reply to requests for deserter information.

“Because they are still at large doesn’t necessarily mean they are still in Japan,” Ford said. “If they are not still in Japan, there is not a lot we can do here locally to find them.”

Still, the missing servicemembers — coupled with the murder last year in Yokosuka — have some Japanese worried about desertion-related crime.

“I want to know the reason [they deserted],” said Emiko Miyamoto, a leader of a women’s civic group in Sasebo called Women Who Will Not Forgive Base Crimes. “They may be desperate, and we don’t know what they’ll do when they are driven into a corner.”

The 12 deserters have not committed any Japanese crimes so far, said Norihiko Kaneko, deputy chief of the U.S. Military Facilities Relations Division for Kanagawa prefecture.

“There are various backgrounds for them becoming a deserter,” said Masashi Suzuki, division chief of Yokosuka city’s Military Base Division. “You can’t say that they are all dangerous.”

Under a new agreement with Japan, any desertion charges must be reported to Japanese police within 72 hours along with a description of the wanted servicemember, including a Social Security number and any tattoos.

“We send it to our liaison over at Yokosuka [police],” said Ensign Shawn Kline, a security officer at Yokosuka. “We continue a 24-hour, seven-days-a-week search for this person.”

Each security shift reviews information about any wanted deserters, and patrol officers and gate guards are advised to be on the lookout for specific deserters during the course of their duties, Kline said.

Yokosuka has resolved five of its seven deserter cases since May 2008, and Japanese police have assisted in two of those cases through information sharing, Flynn said.

U.S. Forces Japan touted the agreement to share deserter information as a “resounding success” in a statement issued Tuesday, and Japanese officials said it helps ease concerns among the public.