Blacks charged with murder, rape and other major crimes are more likely to be acquitted by juries or freed because of a dismissal than white defendants, according to an analysis of Justice Department statistics.

Those results, based on a one-month study by the Center for Equal Opportunity, defy common assumptions about American justice, the author said."Critics of the criminal justice system have alleged that whites are more likely to be acquitted than blacks," said Robert Lerner, a writer and statistical consultant working with CEO. "Despite numerous articles to the contrary, the data . . . suggest that for most categories of crime, juries acquit blacks at a higher rate than whites."

The findings were based on a Bureau of Justice Statistics compilation of results in 55,512 state court felony cases filed in America's 75 largest counties in May 1992. Those counties included many large cities.

"In 12 of the 14 types of crimes for which data was collected (by the Justice Department) the conviction rate for blacks is lower than that of whites," the study said. That included murder, rape, robbery, assault, burglary, drug offenses, weapons charges and "other crimes against persons."

Blacks are convicted at a higher rate for only two categories of crime - felony traffic offenses and for a small number of miscellaneous crimes felonies.

While whites have higher conviction rates overall, including cases that are dropped by prosecutors or voided by judges, there is an even wider gap among cases that reach a jury. Jurors acquitted 83 percent of blacks charged with rape, compared with 24 percent of whites during the month studied .

No whites were acquitted of murder by juries during that time, but juries acquitted 22 percent of blacks. For felony theft, 29 percent of blacks were freed by juries, compared with 22 percent of whites. Of those charged with drug trafficking, 10 percent of blacks were declared not guilty, compared with 7 percent of whites.

Numbers for jury acquittals should, "be viewed with caution," said Lerner, former assistant director of the Center for the Study of Social and Political Change at Smith College. They are relatively small - most criminal cases result in a plea agreement or dismissal - and only a small percentage reach a jury.

But he said overall, the trend of blacks being convicted less than whites is clear.

John Miller, vice president of CEO, a nonprofit research group in Washington, D.C., said there are several possible explanations for the disparity, but said the statistics show some "jury nullification," juries ignoring evidence to acquit based on social or racial factors.

Joseph diGenova, a former U.S. Attorney in Washington, said, "I don't think there is any question that from anecdotal evidence all across the U.S., African-Americans are engaging in jury nullification at a higher level than ever before. This study verifies the anecdotal evidence."

DiGenova said "African-Americans are much more questioning of government authority because of their experiences. But if you are a black victim of crime, and juries are going to discount your harm, that is very troubling."

Jury nullification has backers. A San Diego group Tuesday lost a Supreme Court appeal that would have allowed them to pass out literature advocating jury nullification near courthouses. And an article in the Yale Law Journal by Paul Butler, a law professor at George Washington University, argued that blacks have a moral justification to free black defendants in some cases as long as the system discriminates against them.

Nullification is happening, according to Charles Roistacher, a defense attorney in Washington and former prosecutor. "We've all had cases of out-and-out jury nullification," he said. "Race is a factor in criminal cases, whatever people like to think. Unfortunately it's a reversal of what happened in places like Mississippi in the '50s and '60s."

However, A.J. Kramer, the federal public defender in Washington, D.C., said actual jury nullification is rare.