The Garrity warning is an advisement of rights usually administered by U.S. federal agents to federal employees and contractors in internal investigations. The Garrity warning advises suspects of their criminal and administrative liability for any statements they may make, but also advises suspects of their right to remain silent on any issues that tend to implicate them in a crime.
It was promulgated by the Supreme Court of the United States in Garrity v. New Jersey (1967). In that case, a police officer was compelled to make a statement or be fired, and then criminally prosecuted for his statement. The Supreme Court found that the officer had been deprived of his Fifth Amendment right to silence.
A typical Garrity warning (exact wording varies between federal investigative agencies) may read as follows:
You are being asked to provide information as part of an internal and/or administrative investigation. This is a voluntary interview and you do not have to answer questions if your answers would tend to implicate you in a crime. No disciplinary action will be taken against you solely for refusing to answer questions. However, the evidentiary value of your silence may be considered in administrative proceedings as part of the facts surrounding your case. Any statement you do choose to provide may be used as evidence in criminal and/or administrative proceedings.
The Garrity warning helps to ensure suspects' constitutional rights, while also helping federal agents preserve the evidentiary value of statements provided by suspects in concurrent administrative and criminal investigations.