Use of the death penalty in the United States is coming under a new legal assault, just as the frequency of executions is increasing. There have been five executions this year, two last week. About 1,300 persons are now on death row.
The new legal challenge raises the issue of racial discrimination in the way the death penalty is applied. But the race of the victim, not the race of the offender, is what is at the heart of two new, unpublished studies.
The major conclusion of both studies: People who kill whites are much more likely to be condemned to die than people who kill blacks.
The findings could lead to another landmark ruling by the US Supreme Court on the constitutionality of the death penalty, say some opponents of the penalty, as well as some researchers.
In a 5-to-4 decision in 1972 on a Georgia case, the US Supreme Court ruled that use of the death penalty violates the Eighth Amendment to the Constitution, if it is used ''arbitrarily.''
If it can be shown that the death penalty is being used arbitrarily, in a manner that discriminates against killers of whites, the high court might be faced with another decision. It might have to either establish (or approve) even more guidelines on how the penalty may be applied, or rule it unconstitutional, say William J. Bowers and Glenn Pierce of Northeastern University. The two men have researched various aspects of the use of the death penalty in a number of states.
Today 38 states have death penalty laws, many written after 1972. Data from one of the two new studies - by David Baldus of the College of Law, University of Iowa - was heard this summer in a Georgia death penalty case in a US District Court. The State of Georgia presented a rebuttal by Joseph Katz, a quantitative-methods expert at Georgia State University. No ruling has come yet from that hearing.
On Dec. 13, the US Supreme Court postponed, with only hours to spare, the electrocution in Georgia of Alpha Otis Stephens, a black, to allow time for a federal appeals court to decide whether or not the Baldus data should be heard in a separate death row case.
On Dec. 14, the day before John Eldon Smith, a white, was executed in Georgia , his defense was trying to raise the same racial discrimination issue, but the Supreme Court refused to delay that execution.
Walking along the nation's death rows, past the small cells where the condemned spend most of every 24 hours, it is apparent that about half the cells are filled by whites and half by blacks. So, how could it be argued that the death penalty is used in a racially discriminatory way?
Because, the two new studies conclude, both white and black killers are at least four times more likely to be sentenced to death if they have killed a white person than if they killed a black. In a third study, published in 1980, Professor Bowers of Northeastern made similar findings.
''Society (as a whole) simply values white life more than black life,'' says Samuel Gross of Sanford Law School, a death penalty researcher and author of one of the two new studies.
''It's a form of racism,'' Bowers says. ''A community's evaluation of how serious a crime is depends on whose life was taken,'' he says.
Others note that in many places key judicial officials - prosecutors and judges - are predominantly, and sometimes exclusively, white.
In the Deep South, black prosecutors and black judges are few; often blacks are not represented on juries in the proportion they are present in the area's population as a whole, says Laughlin McDonald, Southeastern regional director of the American Civil Liberties Union.
Stanford's Mr. Gross, an acting associate professor, and doctoral candidate Robert Mauro this summer completed a study of the death penalty in eight states: Georgia, Florida, Oklahoma, North Carolina, Mississippi, Arkansas, Virginia, and Illinois.
They found that between 1975 and 1980 in Georgia, for example, a person who killed a white was more than seven times as likely to get a death sentence as someone who killed a black in an otherwise similar case. In Florida, the chances were five times greater, and in Illinois four times greater when the victim was white.
Mr. Baldus, an attorney and professor of law, examined the records of 1,000 defendants indicted for murder in Georgia between 1973 and 1979 and found:
* 128 of them got the death penalty.
* 85 percent of the condemned had killed a white person.
Then, by carefully comparing 250 factors in cases of similar complication and seriousness, he found:
* For the the average defendant indicted for murder, the odds of receiving a death sentence were approximately four times greater if the victim was white.
* Race of the victim was an important factor in determining the sentence - as important as such things as whether the murder was a multiple stabbing, whether the defendant had a prior felony conviction, or whether the defendant was killing to avoid arrest.
Similar findings have been made for South Carolina.
Raymond Paternoster, assistant professor at the Institute for Criminology at the University of Maryland, found that ''killers of whites are three times more likely to have the death penalty requested (by prosecutors) than killers of blacks.'' He also found that a black who kills a white is five times more likely to get the death penalty than a black who kills another black.