What are common grounds to suppress evidence and how could that help my criminal case?

Common Grounds to File a Motion to Suppress Evidence

In order to successfully file a motion to suppress evidence, you need to have legal grounds to argue that the evidence should be suppressed. These grounds are generally based on police misconduct and violation of your constitutional rights. An experienced criminal defense attorney will be able to identify grounds to file a motion to suppress evidence in your case. Common reasons to file this motion include:

• Unlawful searches and seizures. Under the Fourth Amendment, you are protected against illegal searches of your home, your property, and yourself. In general, police must have a valid search or arrest warrant or probable cause to believe that a crime was committed to stop, search, or arrest you. If the police did not have a proper warrant or probable cause, the evidence collected that supports the charges against you could be thrown out of court.
• Failure to give Miranda warnings. Once the police take you into custody, they must inform you of your Miranda rights under the constitution before questioning you further. This includes being advised of the right to remain silent, that any statements can be used against you, and your right to an attorney. If they fail to give you these warnings and you make an incriminating statement or confess to the crime, these statements can be suppressed. In addition, the police could violate your rights by trying to continue to question you after you invoke your Miranda rights.
• Coerced statements. If the police coerce you into confessing or making a statement, this may be grounds for suppression of your statement.
• Chain of custody errors. The police are required to follow strict procedures for the handling of and storage of evidence against you. This is to ensure that it is not tampered with or mixed up with evidence in another criminal case. When the police mishandle the evidence or otherwise violate the rules, the evidence can be suppressed.
• Witness identification. If you were identified in a police lineup, the police may have violated your rights by improperly suggesting that the witness identify you, failing to allow your attorney to attend the lineup, or failing to include other potential suspects in the lineup with a similar appearance. This can be grounds to suppress the witness’ identification—which could be crucial to proving you committed the crime.
• DUI testing results. There can be many challenges to the tests performed by the police as part of a DUI arrest. This can include violation of the many rules regarding field sobriety tests, improper administration of breathalyzer tests, or calibration problems with testing machines. In addition, many successful challenges to evidence are based on the lack of probable cause to stop the accused in the first place.