Learn
How convictions go wrong, and how they get put right
The same patterns appear again and again, in every country we follow. Knowing them helps you see what might matter in a case.
Flawed forensic scienceExpert evidence that sounded certain and was not.Trial judge errorA legal mistake in rulings or in the instructions to the jury.False guilty pleaSome people plead guilty to get out of custody or avoid a harsher risk.Evidence not disclosedThe defence never saw material that it had a right to see.Fresh evidenceSomething new came to light after the trial.Mistaken identificationAn honest witness can be sincere, certain and wrong.False confessionPeople confess to things they did not do, especially when young, tired or frightened.Unreliable informantJailhouse informants may trade testimony for a benefit.False testimonyA witness lied, or a key account later collapsed.Ineffective lawyerRepresentation so poor that the trial was unfair or the result unreliable.Police or Crown misconductOfficials crossed a line, by act or by concealment.Unreasonable verdictThe evidence could not reasonably support the conviction.Bias or discriminationRace, poverty, disability or prejudice affected the outcome.No crime happenedThe event was an accident, a natural death, or never occurred.
Plain-language glossary
- Acquittal
- A finding of not guilty. Different from a conviction being set aside, which may lead to a new trial.
- Appellant
- The person bringing the appeal. The other side is the respondent.
- Certiorari
- In the United States, a request that the Supreme Court hear a case. Most are refused, and a refusal is not a ruling on the merits.
- Citation
- The reference that lets you find a decision or a statute. Neutral citations, such as 2024 SCC 12, name the year, the court and a number.
- Clemency
- A power held by a head of state, a governor or a minister to pardon or reduce a sentence, outside the courts.
- Conviction Integrity Unit
- A team inside some American prosecutors' offices that re-examines old convictions.
- Direct appeal
- The first appeal after trial, usually based on the record of what happened at trial.
- Disclosure
- The prosecution's duty to hand over relevant material. In the United States this is often called Brady material.
- Elements of the offence
- The specific things the prosecution must prove beyond a reasonable doubt for a crime to be made out.
- Exoneration
- Being officially cleared after a conviction. The exact meaning differs by place and by organisation.
- Extension of time
- Permission to file an appeal after the deadline has passed. Courts can grant these, so a late appeal is not always a lost appeal.
- Factum
- In Canada, the written argument filed in an appeal. Elsewhere it may be called a brief or written submissions.
- Fresh evidence
- Evidence that was not at trial. Courts have strict tests for when they will consider it.
- Habeas corpus
- A court order testing whether someone is lawfully detained. In the United States it is a major route for challenging a state conviction in federal court.
- Ineffective assistance
- A ground of appeal saying the trial lawyer's work fell so far short that the trial was unfair.
- Leave to appeal
- Permission to appeal. Some appeals need it, particularly those to a top court.
- Miscarriage of justice
- A serious failure in the justice process. It is a legal term and does not always mean the person is innocent.
- Neutral citation
- A citation assigned by the court itself, independent of any publisher.
- Notice of appeal
- The short document that starts an appeal. Filing this on time is usually the most important first step.
- Pardon
- An act of mercy by the state. Some pardons recognise innocence, while others simply forgive.
- Post-conviction relief
- In the United States, a collateral challenge to a conviction after the direct appeal has ended.
- Procedural history
- The path a case took through the courts, from charge to the most recent decision.
- Quash
- To set aside. A quashed conviction no longer stands.
- Remittal
- Sending a case back to a lower court to be decided again.
- Standard of review
- How much deference an appeal court gives to the decision below.
- Transcript
- The written record of what was said at trial. Appeals usually depend on it, and legal aid or the court can sometimes help with the cost.
- Unsafe conviction
- The test in England and Wales: a conviction is quashed when the Court of Appeal thinks it is unsafe.
- Vacate
- American term for setting aside a conviction.