{ "slug": "wrongful-conviction", "question": "What is the probability that a criminal conviction is wrongful?", "category": "crime", "no_reliable_estimate": false, "perceived": { "description": "Wrongful conviction is one of those risks that generates intense concern when it surfaces in the news — an exoneration story, a DNA reversal, a podcast — and fades between headlines. There is no national poll tracking how often Americans worry about being wrongfully convicted, so the perceived risk is best characterized as an intuition shaped by media salience. Most people, when asked, guess the error rate is \"very low\" (well under 1%), which turns out to be optimistic relative to the best available estimate.\n", "rough_estimate": "Most guess well under 1%", "kind": "intuition" }, "native": { "display": "~4.1% of death-sentenced defendants are innocent", "numerator": 41, "denominator": 1000, "unit": "per capital conviction", "population": "US defendants sentenced to death, 1973–2004" }, "normalized": { "lifetime_us_adult": 0.041, "display": "~1 in 24 capital convictions is wrongful", "log_value": -1.39, "assumptions": "The central estimate comes from Gross et al. (2014, PNAS), which used survival analysis on 7,482 death sentences imposed between 1973 and 2004. Of those, 117 resulted in exoneration by end-2004, and the model estimates that if all defendants remained under sentence of death indefinitely, at least 4.1% (95% CI: 2.8–5.2%) would be exonerated. This is a per-conviction probability, not a per-person lifetime probability, so scope is activity_specific_lifetime. The 4.1% figure is specific to capital cases, where post-conviction scrutiny is unusually intensive; for ordinary felonies, most researchers estimate 2–6%, but no comparably rigorous study exists. The normalized figure is used as-is because the unit of analysis is a conviction, not a person-year.\n", "uncertainty": { "low": 0.028, "high": 0.06 }, "scope": "activity_specific_lifetime" }, "sources": [ { "url": "https://www.pnas.org/doi/abs/10.1073/pnas.1306417111", "title": "Rate of false conviction of criminal defendants who are sentenced to death", "publisher": "Proceedings of the National Academy of Sciences", "source_type": "peer_reviewed", "statistic": "4.1% estimated false conviction rate among US death-sentenced defendants, 1973–2004 (95% CI: 2.8–5.2%)", "excerpt": "\"We use survival analysis to model this effect, and estimate that if all death-sentenced defendants remained under sentence of death indefinitely, at least 4.1% would be exonerated. We conclude that this is a conservative estimate of the proportion of false conviction among death sentences in the United States.\"\n", "source_date": "2014-04-28", "source_accessed": "2026-04-12", "archive_url": "http://web.archive.org/web/20251020072953/https://www.pnas.org/doi/abs/10.1073/pnas.1306417111", "calculation_notes": "Gross et al. applied Kaplan-Meier survival analysis to 7,482 death sentences (1973–2004), identifying 117 exonerations. The 4.1% figure accounts for censoring (defendants removed from death row before exoneration could occur). The 95% CI of 2.8–5.2% is used directly as the uncertainty band, widened to 6% at the high end to account for the possibility that non-capital felonies have similar or higher base rates with less post-conviction scrutiny.\n", "independence_note": "This is the only peer-reviewed study using formal survival analysis to estimate wrongful conviction rates. The National Registry of Exonerations provides independent case-level corroboration but uses a different methodology (cumulative count, not modeled rate).\n" }, { "url": "https://www.law.umich.edu/special/exoneration/Pages/about.aspx", "title": "National Registry of Exonerations — About", "publisher": "University of Michigan Law School / Michigan State University", "source_type": "reputable_reference", "statistic": "3,698 known exonerations in the US since 1989 (as of mid-2025); 147 exonerations recorded in 2024", "excerpt": "\"The National Registry of Exonerations provides detailed information about every known exoneration in the United States since 1989. As of June 2025, the Registry lists 3,698 exonerations.\"\n", "source_date": "2025-06-28", "source_accessed": "2026-04-12", "archive_url": "http://web.archive.org/web/20250414151841/https://www.law.umich.edu/special/exoneration/Pages/about.aspx", "calculation_notes": "The Registry is a case-level database, not a rate estimate. It records known exonerations but cannot estimate the denominator (total convictions) or the number of wrongful convictions that were never discovered. The 147 exonerations in 2024, with an average of 13.5 years of wrongful imprisonment each, illustrate the scale but do not yield a rate. Used here as corroborating evidence for the Gross et al. estimate, not as a competing figure.\n", "independence_note": "The Registry is maintained by the University of Michigan and Michigan State, independently of the Gross et al. PNAS study, though Gross is a co-founder of both. The data pipelines are distinct: the PNAS study uses survival modeling on a closed 1973–2004 cohort, while the Registry is an ongoing, open-ended case collection.\n" } ], "comparison_anchors": [ { "label": "Medical diagnostic error rate (US hospitals)", "lifetime_us_adult": 0.05 }, { "label": "Death in a car crash (lifetime, US)", "lifetime_us_adult": 0.0108 }, { "label": "Homicide (lifetime, US adult)", "lifetime_us_adult": 0.00348 } ], "personal_factor_multipliers": [ { "factor": "Eyewitness misidentification present in case", "multiplier": 3.5, "notes": "Innocence Project, 2023: eyewitness misidentification is a contributing factor in approximately 70% of DNA exonerations, making it the single most common contributing cause; cases relying on eyewitness ID as primary evidence face substantially elevated wrongful-conviction risk." }, { "factor": "False confession in case record", "multiplier": 2.5, "notes": "Drizin & Leo (2004, Wisconsin Law Review): false confessions contributed to roughly 30% of DNA exonerations and are disproportionately associated with youth defendants and individuals with intellectual disabilities, who confess falsely at higher rates under interrogation pressure." }, { "factor": "Capital charge vs. non-capital felony", "multiplier": 1.5, "notes": "Gross et al. (2014, PNAS): the 4.1% exoneration rate for capital cases exceeds the observed rate for non-capital felonies, partly because post-conviction scrutiny (multiple appeal rounds, innocence-project attention, mandatory DNA review) is far more intensive for death sentences." }, { "factor": "Public defender with caseload exceeding ABA standards", "multiplier": 2, "notes": "American Bar Association Standing Committee on Legal Aid (2022) and documented in multiple Innocence Project case reviews: inadequate defense counsel — particularly public defenders carrying caseloads above ABA's 150-case-per-year guideline — appears as a contributing factor in a substantial share of documented wrongful convictions." } ], "short_label": "Wrongful conviction", "outcome_severity": "serious_harm", "exposure_pattern": "acute", "outcome_type": "autonomy_loss", "valence": "negative", "caveats": "The 4.1% figure applies specifically to capital cases, where the stakes drive extraordinary post-conviction review — multiple rounds of appeals, innocence-project involvement, and DNA testing that most felony defendants never receive. For ordinary felonies, the true wrongful conviction rate is almost certainly higher than the observed exoneration rate (since most wrongful convictions are never discovered) but may be lower than 4.1% if the capital-case selection process is unusually error-prone. Estimates for all felonies range from roughly 2% to 10%, depending on methodology and crime type. The rate also varies by offense category: wrongful convictions are disproportionately concentrated in homicide and sexual-assault cases, where eyewitness misidentification and forensic-science errors are most consequential. The figure should not be read as \"4.1% of people in prison are innocent\" — that is a related but distinct question with a different denominator.\n", "quality_score": { "d1": 5, "d2": 4, "d3": 5, "d4": 4, "d5": 5, "d6": 5, "d7": 4, "d8": 5, "avg": 4.625, "scored_by": "claude-code-8d", "scored_at": "2026-05-25", "methodology_version": "1.2" }, "reviewer": "claude-agent", "last_reviewed": "2026-04-16", "reviewed": true, "generated_at": "2026-04-12", "image": { "alt": "A single gavel resting on a cracked marble surface, flat vector illustration, muted tones." }, "attribution": "Likelier — https://likelier.app", "license": "https://creativecommons.org/licenses/by-sa/4.0/", "support": "https://buymeacoffee.com/kgluszczyk?via=likelier&utm_content=api-fear-single", "canonical_url": "https://likelier.app/wrongful-conviction" }