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DNA - A Prosecutor’s Practice Notebook Inventory

DNA Dragnet

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Conceptual photo of a mass group of people behind dna samples for typing
National Institute of Justice (NIJ) (see reuse policy).

Occasionally law enforcement conducts a DNA dragnet or mass screening in which the public is asked to submit DNA samples for typing in an effort to solve difficult cases. The 4th Amendment requires that law enforcement have probable cause before an individual is arrested or have reasonable suspicion of criminal activity before an individual is detained [Terry v. Ohio, 392 U.S. 1; 88 S. Ct. 1868; 20 L. Ed. 2d (1968)]. However, the 4th Amendment does not prohibit law enforcement from approaching citizens in the community to ask for their cooperation in providing a DNA sample. Consensual contact between law enforcement and the citizens of a community is permitted. [Davis v. Mississippi, 394 U.S. 721 (1969)]. Provided that consent is obtained voluntarily and there has been no coercion, law enforcement may collect voluntary DNA samples for typing.

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