Appeals judges generally resist overruling trial court judgments, instead, preferring to give trial judges the benefit of any doubt. As many appellate courts have said, defendants are not guaranteed "perfect" trials. Normally an appellate court will overturn a guilty verdict only if the trial court made an error of law that appears to have affected the trial outcome. Put differently, an error by the trial judge will not lead to a reversal of a conviction as long as the error can reasonably be considered harmless. Not surprisingly, most errors are deemed "harmless," and consequently few convictions are reversed. However, some errors—like federal constitutional violations—are so grievous that appellate courts presume they are harmful unless proven otherwise by the government.
Sentencing errors are a different matter. When the law gives the trial judge discretion to choose the sentence, the appellate court will rarely interfere. However, if the law requires a particular sentence, and the judge gets it wrong, the appellate court will usually send the case back for resentencing.
In most modern American jurisdictions, a "writ" is an order from a higher court to a lower court or from any court to a government official such as a prison warden. Defendants may seek several types of writs from a court directed at a government official, trial court, or lower appellate court. (Many states have two levels of appellate courts—an intermediate appellate court and the state supreme court.)
Writs, like appeals, are complex and must be written and filed according to jurisdiction-specific rules. Defendants facing situations where they might be entitled to take a writ should consult counsel.
Writs usually are considered to be extraordinary remedies, meaning they are permitted only when the defendant has no other adequate remedy, such as an appeal. Appeals have two main limitations: they are slow and restricted to the trial-court record (the transcripts and documents filed by the parties). These limitations can make an appeal an inadequate remedy when the defendant's situation requires immediate relief or involves evidence outside the trial-court record.
Immediate action required. Immediate relief may be appropriate where a defendant is wrongfully imprisoned (for example, when a defendant is improperly denied bail release). In such cases, many courts view expedited writ proceedings as preferable to the much slower appeals process. An appellate court might also order immediate writ relief in situations where a trial court's improper ruling could have a substantial effect on the defendant's trial. For instance, a trial court's decision to grant or deny a defendant's motion to suppress evidence can not only affect the outcome of the trial but also whether the government has enough evidence to go forward with the trial at all. So if a trial court makes the wrong call on a suppression motion, there's a chance a higher court will grant a writ challenging the trial court's ruling.
Evidence outside the record. Because appeals deal only with issues that are apparent in the case record itself, certain arguments can be made only by writ. For example, ineffective-assistance-of-trial-counsel arguments are often based on evidence that isn't in the trial record. Take, for instance, when an attorney fails to investigate a viable defense. In such a situation, trial counsel's poor performance can affect the outcome of the trial, but the issue probably won't be apparent from looking at the court record. Similarly, evidence of innocence that surfaces after conviction won't be in the trial-court record. So, in both scenarios, a writ might be the defendant's only option for arguing the conviction should be reversed.
Defendants who want to challenge the legality of their imprisonment—or the conditions in which they are being imprisoned—may seek help from a court by filing an application or petition for a "writ of habeas corpus."
A writ of habeas corpus (literally to "produce the body") is a court order to a person (prison warden) or agency (institution) holding someone in custody to deliver the imprisoned individual to the court issuing the order. Many state constitutions provide for writs of habeas corpus, as does the U.S. Constitution, which specifically forbids the government from suspending writ proceedings except in extraordinary times—such as war.
Known as "the Great Writ," habeas corpus gives individuals the power to get help from courts to keep government and any other institutions that may imprison people in check. In many countries, police and military personnel, for example, may take people and lock them up for months—even years—without charging them, and those imprisoned have no avenue, no legal channel, by which to protest or challenge the imprisonment.
The writ of habeas corpus gives jailed suspects the right to ask a judge to set them free or order an end to improper jail conditions. The availability of habeas relief aims to ensure that people in this country will not be held for long times in prison in violation of their rights. Of course, the right to ask for relief is not the same as the right to get relief; courts are very stingy with their writs.
An appeal is a request to a higher (appellate) court for that court to review and change the decision of a lower court. Because post-trial motions requesting trial courts to change their own judgments or order new jury trials are so seldom successful, the defendant who hopes to overturn a guilty verdict must usually appeal. The defendant may challenge the conviction itself or may appeal the trial court's sentencing decision without actually challenging the underlying conviction.