The Veterans Administration has ruled that Medal of Honor winner Sgt. Dwight H. Johnson, shot to death in 1971 in an apparent robbery attempt here was mentally incompetent at the time, the result of his military service.

As a result of the ruling, Johnson's widow, Katrina, is entitled to the same veterans benefits of about $300 a month she would have received had her husband been killed in combat.

The Washington-based Veterans Board of Appeals ruled earlier this month Johnson suffered a mental breakdown, after returning from Vietnam in 1968, receiving the Medal of Honor, and re-enlisting as an Army recruiter.

"He began to feel helpless and not in control of the situation," the three-member board said. "He began to feel that he was being made a fool of, being used, becoming a freak in a side-show, and he felt that he could not trust anyone."

For what the Army called a "magnificent display of courage" while killing a dozen Vietnamese soldiers during a January, 1968, ambush in Vietnam' Central Highlands, it recommended Johnson for the Congressional Medal of Honor the same year. He was Detroit's only Vietnam war Medal of Honor winner and Michigan's first black to receive the nation's highest military honor.

After Johnson received the award, the Army talked him into re-enlisting to recruit other Michigan men. He was required to make public appearances that forced him to relive the very moments of his life he most wanted to forget, according to James Pellegrini, of the Detroit Office of the Disabled American Veterans, who led a two-year battle on behalf of Johnson's widow to get full veteran's benefits.

"He was exposed to a white middleclass society and used by it - exploited," Pellegrini said.

Referring to Johnson's experience as a recruiter, the board said, "He felt ill-prepared for and uneasy about public speeches and appearances. He constantly had to relive the battle and consequent death of his buddies."

According to the VA board's findings, Johnson, at the time of the apparent robbery attempt of Detroit Liquor store, was "completely confused, bitter, distrustful and depressed, and his fellings of inadequacy and helplessness were so overwhelming that he could no longer make a rational decision."

A Detroit psychiatrist, Dr. Bruce Danto, in written testimony before the board, speculated that Johnson's apparent criminal behavior "was an effort to get himself killed."

The benefits are retroactive to July, 1974, when Mrs. Johnson first filed her appeal.