At least 4.1% of people sentenced to death in the US are innocent, a new report warns—and most of them end up neither executed nor exonerated, but serving life behind bars. Researchers say that at a conservative estimate, one in 25 of the thousands of people condemned to death between 1973 and 2004 is innocent and while 138 were exonerated and some were almost certainly executed, up to 200 were taken off death row and are serving life for murders they didn't commit, the Guardian reports.
The researchers—who employed a statistical method often used to assess survival rates of patients treated with new medical therapies—say being moved off death row tends to reduce the chances of exoneration, as the inmates' cases are no longer treated as priorities and they have fewer options for appeals, Scientific American reports. "The great majority of innocent defendants who are convicted of capital murder in the United States are neither executed nor exonerated," the study concludes. "They are sentenced, or re-sentenced to prison for life, and then forgotten."