While the average time spent in prison for all of the exonerees in the National Registry of Exonerations is just over nine years, there have been some prisoners who spent an extraordinary amount of time imprisoned for crimes they did not commit. The Registry calculates prison time from the date of conviction. Therefore, our calculations exclude time spent incarcerated prior to conviction. The following is a list of the exonerees who spent at least 25 years in prison prior to exoneration.
| Name | Time Incarcerated | Sentence | Incarcerated | State |
|---|---|---|---|---|
| Kenneth Gardiner | 25 years, 1 months, 1 days | Life | - | Georgia |
| Mark Jones | 25 years, 1 months, 1 days | Life | - | Georgia |
| Ramon Ward | 25 years, 0 months, 25 days | Life without parole | - | Michigan |
| Kevin Martin | 25 years, 0 months, 20 days | Term of Years | - | District of Columbia |
| Rickey Johnson | 25 years, 0 months, 7 days | Life without parole | - | Louisiana |
| Derrick Sanders | 25 years, 0 months, 6 days | Term of Years | - | Wisconsin |