10 Most Common Grounds to Appeal a Criminal Conviction in California (2025)

The right to a fair trial is enshrined in the U.S. Constitution, and those protections extend to when a trial ends with a guilty verdict. If a defendant was not allowed to properly defend themselves or was negatively impacted by serious legal errors, they have the right to appeal their conviction. Understanding the 10 most common grounds to appeal a criminal conviction in California can help you understand whether you are eligible for an appeal.

1. Ineffective Legal Counsel

Defendants have the right to an attorney during a criminal trial. Along with this right is the assumption that their attorney provides reasonable legal services before and during the trial. Defense attorneys are expected to investigate the allegations, cross-examine witnesses, and present key evidence. If they fail to do so and their client is found guilty, the defendant may have grounds for filing an appeal.

2. Prosecutorial Misconduct

Prosecutors are expected to follow laws, procedures, and disclosure rules before and during a trial. If they have evidence that shows the defendant did not commit a crime, they are required to disclose this exculpatory evidence. They are also barred from making improper remarks to the jury. Prosecutorial misconduct can undermine the integrity of the trial.

3. Judicial Errors

Judges are expected to be neutral arbiters of the law. They ensure that both the defense and prosecution follow court procedures and state laws. If they give misleading instructions to the jury or show bias against the defendant, those actions can deprive the defendant of a fair trial.

4. Insufficient Evidence

The criminal courts have the highest standards when it comes to determining guilt. If a verdict of guilty is rendered based on little to no evidence, the defendant can challenge that ruling on appeal. The appeals court can then review whether the evidence presented in court meets the legal standard for a criminal conviction.

5. Jury Misconduct

Defendants have the right to a trial by a neutral jury. Acts committed by the jury during the trial that demonstrate bias can be used for an appeal. One example would be a juror who took to social media during one of the trial’s breaks to make a post disparaging the defendant.

6. Sentencing Errors

Any sentencing errors can provide grounds for a defendant to file an appeal. State laws provide sentencing guidelines that must be followed. Unauthorized enhancements, for example, could lead an appellate court to order resentencing if an error was found.

7. Improper Admission of Evidence

How and when evidence is admitted is strictly controlled based on evidentiary laws and the discretion of the judge. Any errors made related to what evidence was or wasn’t admitted into evidence could provide grounds for an appeal.

8. Lack of Jurisdiction

If the trial court lacked jurisdiction over the case or the defendant, any resulting conviction is invalid. Appeals can challenge convictions on this basis, asserting that the court did not have the legal authority to preside over the matter.

9. Due Process Rights Violations

Defendants have constitutional protections to ensure a fair trial. If these rights are violated, such as being denied legal counsel, facing biased judicial rulings, or experiencing prosecutorial misconduct, it can compromise the integrity of the case. Any due process violation that affects the trial’s fairness may be grounds for an appeal.

10. Double Jeopardy Violations

Convicting a defendant multiple times for the same offense violates constitutional protections against double jeopardy. If such a violation occurs, it serves as a basis for an appeal to overturn redundant convictions.

FAQs

What Are the Most Common Grounds for a Criminal Appeal?

Criminal appeals are typically based on legal mistakes that affect the outcome of the trial. Common grounds include judicial errors, such as improper jury instructions; prosecutorial misconduct, like withholding evidence; and ineffective assistance of counsel if a lawyer fails to provide a proper defense. Other grounds include jury misconduct, violations of constitutional rights, and the improper admission or exclusion of evidence that influenced the verdict.

How Often Are Criminal Appeals Successful in California?

Criminal appeals are challenging, and most convictions are upheld. However, success depends on the strength of the legal arguments. Appeals that demonstrate clear judicial errors, due process violations, or misconduct have a better chance of leading to a reversal, new trial, or sentence modification. While the overall success rate is low, each case is unique, and an attorney can assess the likelihood of success based on the trial record.

Can a Criminal Appeal Result in a Dismissal of Charges?

Yes, but it depends on the appellate court’s ruling. If the court finds serious legal errors that invalidate the conviction, the charges may be dismissed entirely. However, in many cases, a successful appeal leads to a new trial or a sentence modification instead. If the prosecution lacks sufficient evidence to retry the case, dismissal becomes more likely. An attorney can assess whether dismissal is a possible outcome based on the specific legal errors in the trial.

What Is Considered a Strong Reason for an Appeal?

A strong appeal is based on clear legal errors that directly impacted the trial’s fairness. This could include a judge misapplying the law, improper jury instructions, or key evidence being wrongly admitted or excluded. Constitutional violations, such as a defendant’s right to a fair trial being compromised, also strengthen an appeal. The appellate court must see that the error was not harmless but significant enough to affect the verdict.

What Legal Issues Can Be Used as Grounds for a Criminal Appeal?

Appeals focus on legal mistakes rather than new evidence. Grounds for appeal include judicial misconduct, such as bias in court rulings; prosecutorial misconduct, like suppressing evidence; and ineffective counsel, where a defense attorney’s errors harmed the case. Jury misconduct, sentencing errors, and violations of constitutional rights are also valid legal issues. An attorney can review the trial record to determine which issues apply.

Schedule Your Criminal Appeal Consultation Toda

If your rights were violated during your criminal trial or you witnessed serious legal errors, an appeal can provide you with the relief you are owed. The appellate attorneys at Quinn & Dworakowski, LLP, can review the trial court record, gather supporting evidence, and draft a carefully worded appellate brief that makes clear and concise legal arguments.

A successful appeal can lead to an overturned conviction or an order for a new trial. Our legal team understands how important the appeals process is for serving justice after an unfair trial. We can take swift action so you do not miss critical filing deadlines. Don’t delay. Contact our office today to schedule your criminal appeals consultation.