Study Suspects Thousands of False Convictions
April 19, 2004
By ADAM LIPTAK
A comprehensive study of 328 criminal cases over the last 15 years in which the convicted person was exonerated suggests that there are thousands of innocent people in prison today.
Almost all the exonerations were in murder and rape cases, and that implies, according to the study, that many innocent people have been convicted of less serious crimes. But the study says they benefited neither from the intense scrutiny that murder cases tend to receive nor from the DNA evidence that can categorically establish the innocence of people convicted of rape.
Prosecutors, however, have questioned some of the methodology used in the study, which was prepared at the University of Michigan and supervised by a law professor there, Samuel R. Gross. They say that the number of exonerations is quite small when compared with the number of convictions during the 15-year period. About 2 million people are in American prisons and jails.
The study identified 199 murder exonerations, 73 of them in capital cases. It also found 120 rape exonerations. Only nine cases involved other crimes. In more than half of the cases, the defendants had been in prison for more than 10 years.
The study's authors said they picked 1989 as a starting point because that was the year of the first DNA exoneration. Of the 328 exonerations they found in the intervening years, 145 involved DNA evidence.
In 88 percent of the rape cases in the study, DNA evidence helped free the inmate. But biological evidence is far less likely to be available or provide definitive proof in other kinds of cases. Only 20 percent of the murder exonerations involved DNA evidence, and almost all of those were rape-murders.
The study, which will be presented Friday at a conference of defense lawyers in Austin, Tex., also found that very different factors contributed to wrongful convictions in rape and murder cases.
Some 90 percent of false convictions in the rape cases involved misidentification by witnesses, very often across races. In particular, the study said black men made up a disproportionate number of exonerated rape defendants.
The racial mix of those exonerated, in general, mirrored that of the prison population, and the mix of those exonerated of murder mirrored the mix of those convicted of murder. But while 29 percent of those in prison for rape are black, 65 percent of those exonerated of the crime are.
Interracial rapes are, moreover, uncommon. Rapes of white women by black men, for instance, represent less than 10 percent of all rapes, according to the Justice Department. But in half of the rape exonerations where racial data was available, black men were falsely convicted of raping white women.
"The most obvious explanation for this racial disparity is probably also the most powerful," the study says. "White Americans are much more likely to mistake one black person for another than to do the same for members of their own race."
On the other hand, the study found that the leading causes of wrongful convictions for murder were false confessions and perjury by co- defendants, informants, police officers or forensic scientists.
A separate study considering 125 cases involving false confessions was published in the North Carolina Law Review last month and found that such confessions were most common among groups vulnerable to suggestion and intimidation.
"There are three groups of people most likely to confess," said Steven A. Drizin, a law professor at Northwestern, who conducted the study with Richard A. Leo, a professor of criminology at the University of California, Irvine. "They are the mentally retarded, the mentally ill and juveniles."
Professor Drizin, too, said that false confessions were most common in murder cases.
"Those are the cases where there is the greatest pressure to obtain confessions," he said, "and confessions are often the only way to solve those crimes."
Professor Drizin said that videotaping of police interrogations would cut down on false confessions.
add a comment on this article
add a comment on this article