In the latest study to explore whether race affects who is condemned to die, an examination of 10 years of capital cases in Philadelphia has found that black defendants in certain categories of murder cases there are nearly four times more likely to be sentenced to death than are white offenders.
Supporters of the death penalty immediately challenged the findings. But the research is certain to add to the continuing, heated debate over how fairly capital punishment is administered in the United States.
Opponents of the death penalty hope the study will spur legislation to limit the kinds of crimes that can be punished by death. Proponents said the findings, even if sound, would not hold true outside Philadelphia.
University of Iowa law professor David Baldus did the research, which will be made public today and will be reported in the fall issue of the Cornell Law Review.
Baldus examined 667 Philadelphia murder cases from 1983 to 1993 that could have produced death sentences. Of the defendants in those cases, 520 were black and 147 were white. Ninety-five of the black defendants and 19 of the whites were sentenced to death.
After ranking the crimes by their severity, Baldus found that the defendant's race did not appear to affect the sentence in either the most heinous crimes or in those killings that the researchers considered to be the least likely to produce a death sentence.
But in the mid-range of crimes in which jurors and prosecutors had the most discretion, blacks were four times more likely than whites to be condemned to death, the researchers reported. In Pennsylvania, the jury determines sentencing in capital cases.
"Juries are treating black offenders more punitively, and that is most likely based on a perception of dangerousness associated with being African American," Baldus said in an interview.
"It has been demonstrated in this research and in others," he added, "that when cases are close, the racial factors have a greater impact."
Baldus said the study compared only similar crimes and took into account differences in the defendants' backgrounds and their lawyers.
Critics have generally argued that studies such as Baldus' are invalid because the research relies so heavily on the attempt to compare one murder case with another. Each jury, the opponents argue, has to judge the case in front of it, and one jury's decision cannot fairly be compared with another's.
In 1987, the Supreme Court used that rationale to set aside an earlier Baldus study that found juries in Georgia were more likely to give death sentences to murderers whose victims were white than to those who had killed blacks.
The Philadelphia study also examined the outcome of capital cases by race of victims and found some correlations. But black defendants, regardless of their victims' race, were consistently more likely to be sentenced to die than others, the researchers said.
"The race of the defendant is a much stronger predictor that a case will result in a death sentence than the fact that the crime was committed along with another felony or that the defendant killed with multiple stab wounds," the report concluded.
Baldus and statistician George Woodworth described as "implausible" any contention that their results stemmed from chance or failure to take into account differences in the crimes.
"We believe it would be extremely unlikely to observe disparities of this magnitude and consistency if there were substantial equality in the treatment of defendants in this system," the researchers wrote.
Baldus conceded, however, that the Philadelphia findings might not hold true in other places. "Each state is different and each community is different," he said.
But he added that a smaller study he did in New Jersey found similar results, and race effects also have been found in other research.
Baldus said he chose Philadelphia for the study because the data were accessible, and a lawyers group that helps low-income criminal defendants agreed to help pull the information together.
Philadelphia Deputy Dist. Atty. Ronald Eisenberg said Baldus' methodology has been criticized in the past and questioned whether the professor made subjective findings to reach his results.
"The one thing that is constant is the people who are presenting this [Baldus] material are opposed to the death penalty," Eisenberg said.
He said that crime victims and perpetrators in Philadelphia are disproportionately black.
"The bottom line is that we prosecute cases without regard for the race of the defendant or the victim," he said.
About 80% of the death row inmates sentenced in Philadelphia are black. In California, 44.4% of the inmates on death row are white and 36.1% are black, according to the Department of Corrections.
A spokesman for Atty. Gen. Dan Lungren said two previous studies in California have found that the race of neither the defendant nor the victim influenced death sentencing in the state.
"If you look at the two prior studies looking at California, they clearly show there is no relation between the race of the defendant and whether or not they will be convicted of the death penalty," said spokesman Matt Ross.
The Philadelphia research was one of two studies reported by the Death Penalty Information Center, a nonprofit, Washington-based group that has been critical of capital punishment.
"Race is more likely to affect death sentencing than smoking affects the likelihood of dying from heart disease," the center's report said. "The latter has produced enormous changes in law and societal practice, while racism in the death penalty has been largely ignored."
The other study, to be released today by researchers in Texas, found that 98% of district attorneys who decide which cases to prosecute as capital offenses are white.