On January 20, 1984, Earl Washington—defended for all of forty minutes by a lawyer who had never tried a death penalty case—was found guilty of rape and murder in the state of Virginia and sentenced to death. After nine years on death row, DNA testing cast doubt on his conviction and saved his life. However, he spent another eight years in prison before more sophisticated DNA technology proved his innocence and convicted the guilty man.

DNA exonerations have shattered confidence in the criminal justice system by exposing how often we have convicted the innocent and let the guilty walk free. In this unsettling in-depth analysis, Brandon Garrett examines what went wrong in the cases of the first 250 wrongfully convicted people to be exonerated by DNA testing.

Based on trial transcripts, Garrett’s investigation into the causes of wrongful convictions reveals larger patterns of incompetence, abuse, and error. Evidence corrupted by suggestive eyewitness procedures, coercive interrogations, unsound and unreliable forensics, shoddy investigative practices, cognitive bias, and poor lawyering illustrates the weaknesses built into our current criminal justice system. Garrett proposes practical reforms that rely more on documented, recorded, and audited evidence, and less on fallible human memory.

Very few crimes committed in the United States involve biological evidence that can be tested using DNA. How many unjust convictions are there that we will never discover? Convicting the Innocent makes a powerful case for systemic reforms to improve the accuracy of all criminal cases.

It isn’t enough to celebrate the death penalty’s demise. We must learn from it.

When Henry McCollum was condemned to death in 1984 in rural North Carolina, death sentences were commonplace. In 2014, DNA tests set McCollum free. By then, death sentences were as rare as lethal lightning strikes. To most observers this national trend came as a surprise. What changed? Brandon Garrett hand-collected and analyzed national data, looking for causes and implications of this turnaround. End of Its Rope explains what he found, and why the story of who killed the death penalty, and how, can be the catalyst for criminal justice reform.

No single factor put the death penalty on the road to extinction, Garrett concludes. Death row exonerations fostered rising awareness of errors in death penalty cases, at the same time that a decline in murder rates eroded law-and-order arguments. Defense lawyers radically improved how they litigate death cases when given adequate resources. More troubling, many states replaced the death penalty with what amounts to a virtual death sentence—life without possibility of parole. Today, the death penalty hangs on in a few scattered counties where prosecutors cling to entrenched habits and patterns of racial bias.

The failed death penalty experiment teaches us how inept lawyering, overzealous prosecution, race discrimination, wrongful convictions, and excessive punishments undermine the pursuit of justice. Garrett makes a strong closing case for what a future criminal justice system might look like if these injustices were remedied.