31 Sexual Assault Courts-Martial at Yokosuka, Japan, 2013–2018: What the Records Show

Trends › By Installation › Yokosuka, Japan › Article 120, 2013–2018

Based on 31 cases · 2013–2018 · Navy and Marine Corps records · data updated October 24, 2026

Sexual Assault Cases Were 32% of Yokosuka's Courts-Martial

This page covers courts-martial charging Article 120, the rape and sexual assault article, at Yokosuka, Japan. The 31 cases were 32% of the 96 courts-martial at Yokosuka from 2013 through 2018.

The data runs from January 2013 to August 2018. By year, there were 3 cases in 2013, 8 in 2014, 5 in 2015, 3 in 2016, 7 in 2017, and 5 in 2018. With so few cases, a few cases can change any percentage on this page.

Median Confinement Was 1.8 Years

Of the 31 cases, 21 ended with a conviction on at least one charge. 20 of those sentences included confinement (95%). The median was 1.8 years. In all Navy and Marine Corps Article 120 cases in 2013–2018, it was 3 years. A quarter of the Yokosuka sentences were 3.5 years or longer.

Each figure is an adjudged sentence, set at trial before any plea-agreement cap, clemency, or appeal. A sentence covers every charge in the case, not only the Article 120 charge.

Fewer Sentences of 5 Years or More

11 of 21 convictions (52%) had confinement longer than one year. Across Navy and Marine Corps Article 120 cases, 60% did. 3 convictions (14%) had 5 years or more, compared with 28% service-wide.

Sentences under 6 months were more common here: 33% of convictions, compared with 13% across the service. Only a general court-martial can adjudge more than one year of confinement. A special court-martial is capped at one year.

Pleas and Verdicts

In a contested case, the accused pleads not guilty to at least one charge. At Yokosuka, 24 cases were contested and 7 ended in a guilty plea. The 77% contested share was higher than the 70% for the Navy and Marine Corps as a whole.

All 24 contested cases reached a verdict, and 10 were full acquittals: not guilty on every charge. The 42% rate was lower than the 53% across Navy and Marine Corps Article 120 cases. There were 0 partial acquittals, in which the accused is acquitted of one charge but convicted of another. Navy and Marine Corps records before December 2020 often omit the plea, so these counts use only the records that list it.

Other Charges in Article 120 Cases

Only 6 of the 31 cases charged Article 120 by itself. Article 128 (assault) was charged with it in 25 cases, the most common combination.

Article 120b (child sexual abuse) and Article 80 (attempt) were each in 8 cases. Article 134 (the general article) was in 5, and Article 107 (false official statement) was in 4.

Punitive Discharges

For enlisted members, a punitive discharge is a bad-conduct or dishonorable discharge. 80% of convicted enlisted members received one: 4 bad-conduct and 12 dishonorable. Across the Navy and Marine Corps as a whole, the share was 82%.

The group includes 1 convicted officer or warrant officer, who was dismissed. Dismissal is the officer form of a punitive discharge. Members whose sentence had no punitive discharge can still be administratively separated later.

Rank and Court Level

52% of the accused were NCOs, 42% were junior enlisted members (E-1 to E-4), and 6% were officers. Across the Navy and Marine Corps, junior enlisted members were 48% of the accused, so this group was more senior.

General courts-martial heard 90% of these cases (28 of 31). That is the court level that can impose long confinement and a dishonorable discharge. Special courts-martial heard the rest. A special court-martial can adjudge no more than one year of confinement and no dishonorable discharge.

The Law in Force

These trials took place before January 1, 2019, when the Military Justice Act of 2016 took effect. The act set fixed panel sizes, created judge-alone special courts-martial, and introduced written plea agreements. None of those changes applied here.

Article 120 was rewritten in 2012 and amended again for offenses on or after January 1, 2019. A case is charged under the version in force on the date of the offense.

What the Records Do Not Show

Trial records show charges, pleas, findings, and sentences. They do not show the evidence, the plea terms, or the offense dates. Allegations handled without a court-martial are not included.

For what the offense covers and how it is defended, see Article 120 on the law firm's website. Dates and sources for the law changes: UCMJ change timeline.

Compare: federal court. Sexual Abuse of an Adult: Federal Cases vs. Article 120 Courts-Martial

About the author. Jocelyn C. Stewart is a retired Army JAG with more than 24 years of trying courts-martial and more than 200 jury trials. She hosts Where All The Bodies Are Buried and runs the Law Office of Jocelyn C. Stewart. This analysis is for education and information only. It is not legal advice, and every case is different.