May the police use information from a confidential informant against me?

Confidential informants are people who supply information to the police without having their identities disclosed. The law allows police to use such information if it is reliable. The police often use such information to obtain search warrants. For example, an informant might tell the police where someone has hidden evidence of a crime. The police will provide this and other information (such as the informant's prior reliability, how the informant obtained the information, and evidence obtained from other sources that confirms the informant's story) to a judge or magistrate (a type of court official). If the judge or magistrate determines there is probable cause to believe that this evidence will be found at the location specified, the judge or magistrate will issue a search warrant. The prosecutor must not reveal the confidential informant's identity unless he or she is ordered to do so by the court. In addition, the prosecutor can ask the judge for a protective order sealing the warrant and the supporting affidavit to keep the identity of the informant secret.
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