In order to strengthen the confidential nature of the attorney-client privilege and support a bond of trust between attorney and client, some courts have fashioned an attorney-client privilege that shields from disclosure certain communications between a client and his or her attorney. The theory of attorney-client privilege dates back to Roman law and was recognized by English common law as early as the 16th Century.
The attorney-client privilege is an evidentiary rule that protects both defense lawyers and defendants from being compelled to disclose confidential communications between them that are made for the purpose of furnishing or obtaining legal advice or assistance. This privilege is designed to foster frank, open and uninhibited discourse between the defense lawyer and the defendant so that all of the defendant's legal needs are competently addressed by a fully informed defense lawyer. The attorney-client privilege protects defendants by allowing them to tell their attorney the truth of every detail of their case without fear of having more charges brought against them. Without this rule, a prosecutor could easily convert a defense attorney into a witness.
The attorney-client privilege is the first of two doctrines by which the confidentiality of communications with the client is protected. The second doctrine is the work product doctrine. Where the work product doctrine is meant to protect from disclosure documents prepared by a lawyer for or in anticipation of going to trial, attorney-client privilege is a far broader protection that covers a wide variety of communications by a client to his or her lawyer.
Elements of the Attorney-Client Privilege
The essential elements of the Attorney-Client Privilege may vary between jurisdictions. Generally the following elements are required:
- The individual who claims the privilege is either: (A) a client of the defense attorney or (B) engaged in confidential communications in order to become a client of the defense attorney.
- The individual to whom the client communicated was an attorney or an agent of the attorney.
- The attorney was acting in their legal capacity
- The communication must be between the attorney and client exclusively
- The communication was for the purpose of securing legal advice. Attorney-Fees are not considered "legal advice".
Importantly, the privilege must be asserted by the client - it cannot be asserted on the client's behalf by the attorney. The defense lawyer does not have the power to prevent the defendant from choosing to waive the privilege and testify in court, talk to the police, or otherwise share confidential attorney-client information with third parties. Similarly, attorney-client privilege only covers communications made by the client to the attorney. However, many communications made by the attorney to the client will reflect earlier client to attorney communications and may be covered by the evidentiary privilege.
Importantly, only the communications pertaining to advice, and not the underlying facts, are protected by the attorney-client privilege. Although attorney-client privilege is sometimes described as "inviolate," this description is misleading. In fact, the attorney-client privilege may be broken by:
- Waiver - The communication was made in the presence of a third party in such a way that suggests the communication was not intended to be confidential. This waiver can be made expressly by the client's words or implicitly by the client's conduct. Generally a court will only find that the privilege has been waived if there is a clear indication that the defendant did not take steps to keep the information confidential. Inadvertent or accidental disclosure of confidential information will not generally constitute a waiver.
- Crime Exception - Some jurisdictions hold that a confidential communication is not covered if the communication was made for the purpose of committing another wrong. The attorney-client privilege is designed to serve the interests of justice and must not be used to protect acts in furtherance of a crime. A party seeking discovery of privileged communications based on the Crime Exception must make a specific showing that a particular document or communication was made in furtherance of the client's alleged wrongdoing or else the attorney-client privilege will stand. Some specific examples of wrongdoing include:
- Death or Substantial Bodily Harm - The defense attorney may be required to disclose communications if doing so would prevent reasonably certain death or substantial bodily harm.
- Fraud - The defense attorney may be required to disclose communication if defendant is using the defense attorney's advice to commit a future crime substantially certain to result in substantial economic injury.
- Mitigation or Repair - The defense attorney may be required to disclose confidential communication if doing so would mitigate or rectify ongoing economic injury and the client is using defense attorney's services to further the harm.
- Self-Defense - The attorney-client privilege will not apply in cases where the criminal defense attorney is being sued by the defendant for ineffective assistance of counsel, malpractice or any other dispute between the parties that requires disclosure of otherwise confidential communications.
- Non-legal Capacity - When an attorney is not acting primarily as an attorney, but, for instance as a business advisor or member of a Board of Directors, then the attorney-client privilege does not apply.
Duties to Former Clients
The duty of confidential communication continues beyond the attorney-client relationship. The same duties apply to former clients as do to current clients. An attorney should not take a case where doing so would create a conflict of interest with the former client. A conflict would arise if the defense attorney represented another client on the same or a substantially related matter in which the clients interest is materially adverse to interest of former client. A former client may waive the conflict through informed, written consent.
In U.S. practice, the attorney-client privilege is one of the oldest recognized privileges for confidential communications. The United States Supreme Court has stated that by assuring confidentiality, the privilege encourages clients to make "full and frank" disclosures to their attorneys, who are then better able to provide candid advice and effective representation. The attorney-client privilege may be raised at any time during criminal proceedings, pre-trial, during trial or post-trial. The American Bar Association has referred to attorney-client privilege as "the bedrock of the client's constitutionally based right to effective assistance of counsel." 
In the United States, the rules of evidence for proceedings before federal courts, including "the courts of the United States, and before United States bankruptcy judges and United States magistrate judges" are governed by the Federal Rules of Evidence. Rule 501 of the Federal Rules of Evidence provides that unless otherwise provided for by the Constitution or federal statute, "the privilege of a witness, person, government, State, or political subdivision thereof shall be governed by the principles of the common law as they may be interpreted by the courts of the United States in the light of reason and experience."  The principles of federal common law that govern attorney-client privilege are substantially similar to the common elements discussed above in section 2. The Federal Rules of Evidence also codifies the rule that inadvertent disclosure of confidential information will not, in and of itself, waive attorney-client privilege. 
However, in civil cases where state law governs the elements of a defense or claim, the state law also governs privileges. Individual state's court rules, case law and legislation will each have a nuanced approach to the application of attorney-client privilege. A sample of individual state court decisions based at least in part on their own state's court rules, case law and legislation can be found here.
Additional Country Resources
A broad selection of articles regarding attorney-client privilege by country is available here.
- Attorney-Client Privilege, enotes.com, available at http://www.enotes.com/everyday-law-encyclopedia/attorney-client-privilege
- Criminal Defense and Attorney Client Privilege, CriminalDefenseLawyer.com, available at http://www.criminaldefenselawyer.com/criminal-case-guide/criminal-defense-attorney-client-privilege.htm
- Upjohn Co. v. United States, 449 U.S. 383, 395 (1981)
- See, e.g., Clark v. United States, 289 U.S. 1, 15 (1933) ("A client who consults an attorney for advice that will serve him in the commission of a fraud will have no help from the law. He must let the truth be told."
- Swidler & Berlin v. United States, 524 U.S. 399, 403 (1998)
- Upjohn Co. v. United States, 449 U.S. 383, 389 (1981)
- Answers to Questions about the Attorney Client Privilege, ABAnet.org, available at http://www.abanet.org/media/issues/acprivilegeqa.html
- Federal Rules of Evidence - Rule 101. Scope
- Federal Rules of Evidence - Rule 501. General Rule
- Federal Rules of Evidence - Rule 502. Attorney-Client Privilege and Work Product; Limitations on Waiver