Frequently, when an individual is criminally charged, the prosecution will seek to use evidence obtained from a search. Federal Agents conduct searches both with, and without, a search warrant. A court may issue a search warrant if there is a finding of "probable cause," i.e., whether there is a fair probability that contraband or evidence of a crime will be found in a particular place.

A criminal defense lawyer will commonly contest the legality of a search by filing a motion to suppress evidence obtained from the search. The laws regarding searches, both with and without a search warrant, can be very technical, and are fact-based. For example, laws regarding whether a warrantless search is legal vary based on a number of factors, including, whether: the search was incident to a valid arrest; the seized items were in "plain view;" there were "exigent circumstances" to justify a warrantless search; there was consent to search; a vehicle was searched; a container was searched; the search occurred at an international border; the search occurred on the high seas; and there was an abandonment of the property seized.

Motions to suppress evidence may be effective even if the federal agents obtained a search warrant prior to the search. Certain defects either in obtaining the search warrant, or in executing the search, could result in the suppression of the evidence.

Commonly, during a search, federal agents will question the individuals searched or those present at the site of the search. Regardless of whether such search is pursuant to a search warrant, these individuals maintain all their constitutional rights, including the right not to incriminate one's self.

Remember, what you say can be used against you, and in ways that may not be initially apparent.