Evidence can be suppressed (that is, not allowed to be used in court) for a number of reasons. Both legal and illegal actions can lead to suppression. Below, Evidence Suppression is defined, and its many causes delineated. Suppression functions the same way in both violent and White Collar crimes.
Evidence suppression occurs under one of two conditions. The first is when a judge declares evidence “inadmissible” (meaning it cannot be presented to a jury during trial). This is called “legal suppression.” The second condition occurs when a prosecutor violates his constitutional responsibility to share all evidence with the defense, or vice versa. This is called “illegal suppression.” The most common cases of suppression fall under the former category. A judge can declare evidence inadmissible if it was gathered by police through illegal means, such as when a warrant is not obtained.
Evidence collection without either a warrant or probable cause falls under a suspect’s rights against “unreasonable search and seizure” (as established by the Fourth Amendment). Evidence obtained during a police interrogation in which a suspect is not mirandized (informed of his “Miranda rights” under the Fifth Amendment) can also be suppressed by a judge. Evidence obtained through police coercion can likewise be thrown out. Additionally, evidence obtained after the suspect requests an attorney, but before that attorney arrives, is usually not allowed in court.
In federal court, but not in Texas courts, the following exceptions apply to the above rules. If it is determined that illegally-obtained evidence would have inevitably been discovered legally, it is usually allowed. If both legal and illegal means were used for obtaining it, and if the legal means would have led to the same discovery, it is still admissible. This is also the case if evidence is obtained illegally through no fault of the police. Finally, illegally-obtained evidence is often admissible if it has little impact on the case, such as when it comes from another investigation.
Prosecutors or defense attorneys who knowingly suppress evidence that is otherwise admissible can face criminal charges, disbarment, and contempt of court. This form of suppression is a violation of the Fifth and Fourteenth Amendments, which guarantee a suspect’s right to due process. Under these circumstances, charges may be dismissed or the judge may declare a mistrial.