Evidence is the foundation of every criminal case. When law enforcement and the prosecution mishandle evidence during collection, analysis, or presentation, it often leads to wrongful convictions. How does this happen—and what can you do?
Examples of Mishandling Evidence
Mishandling evidence can lead to inaccurate conclusions. For instance, if law enforcement cross-contaminates DNA evidence, a completely innocent person’s genetic material could appear to link them to a crime. Improper handling can occur at any stage of the criminal process. Common examples include:
- Failing to collect key physical evidence from a crime scene03
- Losing or destroying evidence before the defense has a chance to see it
- Contaminating biological (for example, blood, hair, urine, DNA, saliva) samples06
- Improperly labeling or storing evidence
- Failing to document the chain of custody
- Allowing unauthorized people access to evidence
- Tampering with or altering records, photos, or digital files
Mishandling evidence can violate a defendant’s Constitutional rights. When evidence is lost or destroyed in bad faith, it can result in sanctions or dismissal.
Why the Chain of Custody Is So Important
Evidence has to be tracked from the moment it’s collected until it’s presented in court. Each person who handles the evidence must document when, where, and how they received and transferred it. This is called the “chain of custody.”
If the chain of custody is broken (inaccurate or incomplete), the evidence may not be admissible in court.
In practice, a broken chain of custody could be an officer failing to sign a log when transferring a sealed bag of drugs to a lab, or a technician leaving a sample unsealed overnight. Even small lapses cast doubt on whether the evidence came from the crime scene or has been altered.
How Mishandling Evidence Can Lead to a Wrongful Conviction
When law enforcement and the prosecution mishandle evidence, it distorts the truth in multiple ways. Physical evidence might falsely suggest guilt. Digital evidence could be altered or deleted. Witness testimony based on unreliable forensic reports can convince a jury that the wrong person is responsible for a crime.
Forensic errors are a major factor in wrongful convictions nationwide. According to the Innocence Project, 43% of DNA exonerations from 1989 to 2020 involved some form of misused or mishandled forensic evidence. Mistakes like mixing up samples or mislabeling fingerprints can have life-altering results.
Once a conviction is entered, correcting it is extremely difficult. Michigan’s post-conviction relief process allows for challenges based on newly discovered evidence or Constitutional violations, but exonerations often take years.
Brady Violations
Law enforcement officers have a duty to preserve all potentially relevant evidence, including items that could exonerate a suspect. Prosecutors must share exculpatory evidence with the defense, thanks to the Supreme Court case Brady v. Maryland (1963).
When police or prosecutors fail to disclose or protect this evidence, it’s called a Brady violation. Brady violations are a violation of due process. For example, if police erase dashcam footage or fail to test a firearm for fingerprints, the defense may lose key opportunities to challenge the state’s case.
What To Do To Protect Your Rights
If you suspect that evidence in your case was mishandled, raise the issue as soon as possible. Your attorney can file motions to suppress unreliable evidence or demand discovery of missing materials.
Even if the court doesn’t throw out the evidence, exposing the mishandling can weaken the prosecution’s case. Once jurors learn about the mistakes, they may be skeptical of the prosecution’s claims.
Discuss Your Case With an Experienced Criminal Defense Lawyer Today
If you believe evidence in your case was lost, contaminated, or mishandled, you have the right to challenge it. Mueller Law Firm helps clients across Michigan hold the state accountable when due process is violated. Contact us to explore your legal options.
