What Evidence Can Support a Criminal Appeal?
When someone's been convicted of a crime, the legal process doesn’t necessarily end there.
A criminal appeal gives them a chance to challenge the outcome of their case based on legal errors or new evidence. Appeals aren’t about re-trying a case but rather about showing that something went wrong in the original trial that impacted the verdict or sentence.
One of the most important parts of a criminal appeal is the evidence used to support it. Not all evidence can be introduced at this stage, so it’s important to understand what can be used and how it might help.
At JP Law in Kansas City, Missouri, I can help you understand different types of evidence that can support a criminal appeal and how they fit into the appeals process.
An Overview of the Criminal Appeals Process
Before getting into what evidence can support an appeal, it’s helpful to understand how the appeals process works. Unlike a trial, a criminal appeal doesn’t involve witnesses or juries. Instead, appellate courts review the case to determine whether legal errors occurred that could have influenced the outcome. This process generally involves:
Filing a notice of appeal: The first step is for the defendant or their attorney to file a formal notice of appeal within the required deadline.
Compiling the trial record: The court gathers transcripts, evidence, and legal documents from the original case for review.
Submitting appellate briefs: Both sides submit written arguments explaining why the conviction or sentence should be upheld or overturned.
Oral arguments: In some cases, attorneys present their arguments in court and answer judges’ questions.
The appellate court’s decision: The court can uphold the conviction, overturn it, order a new trial, or modify the sentence.
Since appellate courts rely on legal arguments rather than new testimony, the evidence used must fit within strict guidelines. Below are some key types of evidence that can play a role in an appeal.
Errors Made During the Trial
Sometimes, a conviction happens because of mistakes made by the judge, prosecutors, or defense attorneys. These errors can be strong grounds for an appeal if they had a significant impact on the outcome of the case.
Judicial errors: If a judge misinterpreted the law, improperly admitted or excluded evidence, or gave incorrect jury instructions, these mistakes could be grounds for an appeal.
Prosecutorial misconduct: If the prosecution acted unfairly — such as withholding evidence, presenting false testimony, or making improper arguments — this can be used as evidence for an appeal.
Ineffective assistance of counsel: If a defense attorney made serious mistakes, failed to investigate evidence, or didn’t provide adequate representation, this can support an appeal.
Jury misconduct: If jurors discussed the case outside the courtroom, were biased, or engaged in improper behavior, this could be a valid argument for an appeal.
Legal errors can make or break a case, so showing that they happened is often a key part of an appeal. But errors aren’t the only thing that can be used to challenge a conviction.
New or Newly Discovered Evidence
Sometimes, new evidence comes to light after a trial that could change the outcome of a case. If this evidence wasn’t available at the time of trial and could have led to a different verdict, it might serve as the basis for a criminal appeal.
DNA or forensic evidence: Advances in forensic science can uncover errors in prior testing or introduce new evidence that wasn’t available during the original trial.
Witness recantations: If a key witness admits they lied during testimony, this could be significant evidence for an appeal.
New witnesses: If someone comes forward with information that wasn’t previously known, their testimony might support the appeal.
Exculpatory evidence previously withheld: If prosecutors failed to disclose evidence that could have helped the defense, this could justify overturning a conviction.
Video or digital evidence: If new security footage, phone records, or other digital evidence comes to light, it could impact the outcome of a case.
New evidence must be compelling and credible to have an impact. But even if there isn’t new evidence, other factors — like constitutional violations — can still support an appeal.
Violations of Constitutional Rights
Every person accused of a crime has constitutional rights, and if those rights were violated, it could be grounds for an appeal.
Illegal search and seizure: If law enforcement obtained evidence without a proper warrant or probable cause, that evidence might have been improperly used in court.
Violation of Miranda rights: If a suspect wasn’t properly informed of their right to remain silent or to have an attorney, their statements might be inadmissible.
Denial of the right to a fair trial: If there was jury misconduct, biased jurors, or other issues that prevented a fair trial, this could support an appeal.
Ineffective assistance of counsel: This isn’t only a trial error but also a constitutional issue under the Sixth Amendment.
Coerced confessions: If a confession was obtained through force, threats, or prolonged interrogation, it might be inadmissible in court.
Constitutional violations can be powerful grounds for a criminal appeal, but they must be well-documented. The next section will cover how mistakes in sentencing can also play a role.
Sentencing Errors
Even if a conviction itself isn’t overturned, sentencing errors can sometimes lead to a reduced sentence or a new sentencing hearing.
Sentencing outside the guidelines: If a judge imposed a sentence that was harsher than allowed by law, it could be corrected on appeal.
Improper consideration of evidence: If a judge based the sentence on unreliable or inadmissible evidence, this could be grounds for appeal.
Failure to consider mitigating factors: If the court ignored important factors—such as a defendant’s lack of criminal history or circumstances that lessen their culpability — this might support a sentencing appeal.
Double jeopardy violations: If a defendant was punished multiple times for the same offense in violation of constitutional protections, this could be corrected.
Sentencing appeals focus on making sure the punishment fits the law and the facts of the case. But once an appeal is filed, what happens next?
How Appeals Are Reviewed
Once a criminal appeal is filed, an appellate court reviews the case to determine if errors occurred. This review is based on the trial record, legal briefs, and sometimes oral arguments. No new evidence is introduced, but the court evaluates whether legal mistakes were made that affected the outcome.
Appellate briefs: Attorneys submit written arguments explaining why the conviction or sentence should be overturned.
Oral arguments: In some cases, attorneys present arguments in court and answer judges’ questions.
Review of trial records: The appellate court examines transcripts and evidence from the original trial to determine if errors occurred.
Possible outcomes: The court can uphold the conviction, overturn it, order a new trial, or modify the sentence.
A strong appeal requires solid legal arguments backed by evidence of errors or violations. This process can be lengthy, but it’s an important avenue for those who have been wrongfully convicted or unfairly sentenced.
Contact a Criminal Defense Attorney Today
A criminal appeal isn’t about proving innocence all over again — it’s about showing that something went wrong in the legal process that led to an unfair outcome.
While the appeals process can be difficult, JP Law can make a difference. I serve clients in Clay County, Jackson County, Independence, Liberty, and Kansas City, Missouri. Call today for a free consultation.