WASHINGTON - A comprehensive study of 23 years of capital punishment has

found that more than two-thirds of America's death sentences are overturned

on appeal, leading the report's author to conclude that this country has a

''broken system'' that is ''fraught with error.''

In one of the most exhaustive studies of capital punishment ever, James

Liebman, a Columbia University law professor, found that just 5 percent of

the 5,760 inmates sentenced to death in the United States between 1973 and

1995 were executed within the study period. And when capital cases were sent

back for a new trial, 7 percent of the defendants were found not guilty, and

fewer than two in 10 of those who were convicted again got another death

sentence, the study found.

Death penalty supporters interpreted the numbers differently than Mr.

Liebman. They say the report proves that there is only the slimmest of

chances of executing an innocent person because the appeals courts subject

the cases to extraordinary scrutiny. They also note that 93 percent of those

inmates retried were convicted again, though many received a lesser

sentence.

Nine years in the making, Mr. Liebman's study is adding fuel to an already

fiery debate about capital punishment in America. Although executions have

reached record numbers, public support is at a 19-year low. And voices from

across the political spectrum have begun to question whether those on death

row received fair trials.

Illinois has halted executions while a commission tries to determine why

more inmates have been exonerated than executed there. The Republican

governors of Virginia and Texas this month ordered new DNA tests for men who

say they did not commit the crimes for which they were sentenced to death.

And last week, the governor of Maryland, Parris Glendening, a Democrat,

commuted a death sentence because he was not completely sure of the guilt of

a death-row inmate, Eugene Colvin-el.

''It's not just one case, it's not just one state. Error was found at

epidemic levels across the country,'' Mr. Liebman said. ''From the point of

view of a taxpayer, I am paying all this money for capital punishment, and

they're managing to carry out just one in 20 death sentences.''

Charles Baird, a former judge on the Texas Court of Criminal Appeals who

recently joined a national group seeking death penalty reforms, agreed. ''I

knew the system was terribly flawed, but I was shocked at the numbers,'' he

said.

But Josh Marquis, an Oregon prosecutor who sits on the board of the National

District Attorneys Association, said the numbers ''confirm that the system

is working,'' adding that ''mistakes that are made by prosecutors and judges

are caught.''

Dudley Sharp, a director of the Texas-based reform group Justice for All,

pointed out that the study covers a period when rules for capital punishment

were changing rapidly. ''As time goes on, we will see fewer and fewer cases

overturned as the law becomes more established,'' he predicted.

To determine why death sentences were overturned, the study looked closely

at every case that was sent back during a second round of state appeals. In

37 percent of reversals at that stage, appeals courts ruled that defendants'

attorneys were so bad that their performance substantially altered the trial

outcome. Misconduct by prosecutors - who suppressed exculpatory or

mitigating evidence - accounted for 16 percent of the reversals.

Those figures suggest the need for national standards for defense lawyers

and rules making

post-conviction DNA testing available to all death row inmates, said Senator

Patrick Leahy, Democrat of Vermont, who is sponsoring a bill that would make

both the law.

Mr. Liebman argues that the frequent reversals harm the families of murder

victims by adding uncertainty and by forcing them to sit through retrials.

Victims advocates agree, but they said capital punishment was not the

problem. Rather, they said, the study simply emphasized the need to handle

cases right the first time.

''The system of protecting the rights of accused is good,'' said Stanley

Rosenbluth, who founded Virginians Against Crime after his son and

daughter-in-law were murdered in 1993. ''It's the people who are

administering it who need improvement: The judges that make mistakes and

don't permit evidence to be introduced.''

He added: ''We also need improvement of the defense attorneys.''

The Columbia study also highlighted significant disparities among the states

with capital punishment. During the study period, for example, none of

Maryland's 60 death sentences survived judicial review. The lone person

executed had given up his appeals and agreed to die. Virginia, on the other

hand, executed 28 percent of the 105 people sentenced to death in the study

period, the highest ratio in the nation.

Texas had a reversal rate of 52 percent, the study found. Illinois, which is

sometimes described as unusually troubled, is about average: 66 percent of

death sentences were overturned during the study. The national reversal rate

is 68 percent. ''If you had a hospital where two-thirds of their surgeries

were wrong, how long would it take to close it down?'' Mr. Leahy asked. ''We

should have zero tolerance for mistakes.''

(source : International Herald Tribune)