Understanding the Preservation of Evidence in Criminal Cases

Today we’re talking about understanding the preservation of evidence in criminal cases. When people are criminally prosecuted in Pennsylvania, the government must preserve the evidence that it gathers during criminal investigations to protect the due process rights of defendants. The duty to preserve evidence also includes a mandate for the government to disclose the evidence that it plans to use against defendants at trial. It must also disclose any mitigating evidence that it uncovers that could help the defense. This duty begins when any state agency has collected evidence during a criminal investigation. A criminal defense lawyer at DiCindio Law understands how to secure the required disclosures to help to build defense cases for defendants.

Types of evidence that must be preserved

The duty for preservation of evidence in criminal cases does not mean that police officers must preserve all of the information and evidence that they collect. Instead, the duty applies only to the evidence that is exculpatory and material. Exculpatory evidence includes evidence that tends to clear the defendant of guilt. Material evidence includes any relevant evidence that directly relates to the issues in a criminal case.

One type of evidence that is nearly always both exculpatory and material is alibi evidence. This type of evidence includes things like forensic evidence that demonstrates that the defendant could not have committed the offense and witness statements that the defendant was located somewhere else at the time the crime was committed.

Other types of material and exculpatory evidence

Many cases don’t have alibi evidence. However, they may have other types of material and exculpatory evidence that tends to weaken the state’s case against a defendant. 

Some examples of other types of material and exculpatory evidence include the following:

  • Evidence from the crime scene, including photographs, murder weapons, blood samples, and measurements
  • Video and audio recordings
  • Investigative notes made while interrogating a defendant
  • 911 call recordings

Who must preserve evidence?

Several parties must preserve evidence that is collected in a criminal case, including the following:

  • Detectives, investigators, forensic staff, clerical staff, and administrative staff of investigative agencies
  • Prosecutors, prosecution experts, and prosecution investigators
  • Attorney general for appeals and post-conviction matters

Private agencies and individuals do not have a duty to preserve evidence unless they have formal relationships with law enforcement agencies. If a prosecutor hires a private lab to perform DNA analysis, the lab will have to preserve the evidence and the results of the tests that it performs because of the relationship it has with the prosecutor’s office.

Evidence that is destroyed or lost

The burden of proving that the state violated the duty to preserve evidence lies with the defendant. A defendant will have to show that the state’s violation of its duty interfered with his or her right to a fair trial and due process. To get the court to take action, a defendant will need to show that the evidence that was lost or destroyed was material and exculpatory. The defendant will also have to prove that the state acted in bad faith in destroying or losing the evidence in question.

To prove that lost or destroyed evidence was material, a defendant will need to be able to show that the police officers knew or should have known that the evidence was exculpatory before it was destroyed. The defendant will also need to show that the evidence cannot be replaced by other available evidence.

The materiality of the evidence can sometimes be inferred from the actions of the officers. For example, if the officers destroyed evidence that was a type that is normally preserved in similar cases, the materiality of the evidence might be inferred by the court. The court might also infer that the evidence was material if the state tested, used, or intended to test the evidence that was lost or destroyed.

It is difficult to prove that the state acted in bad faith in losing or destroying evidence. Simply showing that the officers were negligent or careless is not enough. Instead, the defendant must demonstrate that the officers acted willfully, maliciously, or deceitfully. Bad faith can be inferred when the state failed to follow standard procedures. An example of an investigator’s bad faith might include destroying DNA samples that tend to show that someone else committed the crime.

Remedies when the state destroys or loses material and exculpatory evidence

The prosecution will not be sanctioned by the court if it loses or destroys material or exculpatory evidence unless the defendant raises the issue. Normally, a defendant will file a motion with the court to notify it, and the court will schedule a motion hearing. At the hearing, the defendant will have to present evidence showing that the government has violated its duty to preserve evidence and acted in bad faith. The defendant will also need to present evidence showing that the destroyed or lost evidence was material and exculpatory to the extent that his or her constitutional rights to a fair trial and due process were violated.

If the defendant is successful, the court may limit testimony about related evidence or suppress it. In extreme situations, the court may dismiss the charges against the defendant. When the destruction of evidence is not discovered until after a conviction, the conviction may be overturned by an appeals court.

When the defendant discovers during his or her trial that the prosecution violated the duty to preserve and disclose evidence, there are a couple of remedies. The defendant can ask the court to exclude or restrict testimony about the destroyed or lost evidence, suppress related evidence, or dismiss the charges.

Contact DiCindio Law

The preservation of evidence in all criminal cases are critical for ensuring that people receive fair trials. People who are charged with crimes might want to retain experienced criminal defense lawyers for help with ensuring that all of the relevant evidence is disclosed to them. Contact a criminal defense lawyer at DiCindio Law today by calling us at (610) 430-3535.