In 1989, Texas executed Carlos DeLuna, a poor Hispanic man with childlike intelligence, for the murder of Wanda Lopez, a convenience store clerk. His execution passed unnoticed for years until a team of Columbia Law School faculty and students found that DeLuna almost certainly was innocent. This book documents DeLuna's conviction, which was based on a single, nighttime, cross-ethnic eyewitness identification with no corroborating forensic evidence. DeLuna's defense, that another man named Carlos had committed the crime, was not taken seriously. The evidence the Columbia team uncovered reveals that Hernandez not only existed but was well known to the police and prosecutors. He had a long history of violent crimes similar to the one for which DeLuna was executed. This book and its website (thewrongcarlos.net) reproduce law-enforcement, crime lab, lawyer, court, social service, media, and witness records, documenting one of the most comprehensive investigations into a criminal case in U.S. history. The result is eye-opening yet may not be unusual. Faulty eyewitness testimony, shoddy legal representation, and prosecutorial misfeasance continue to put innocent people at risk of execution. The principal investigators conclude with novel suggestions for improving accuracy among the police, prosecutors, forensic scientists, and judges.