The discussion opens with a description of the privilege to use deadly force at common law and under the statutes that now govern the matter in most jurisdictions. It is then shown why the distinctions between suspects involved in the use of deadly force do not violate the equal protection clause. The article also demonstrates that the fourth amendment's prohibition of unreasonable seizures does not provide an adequate doctrinal foundation for the imposition of significant limits on the use of deadly weapons. The use of deadly force under the guarantees of substantive and procedural due process is then examined. Although due process doctrine, like fourth amendment doctrine, supplies no precedent for distinguishing among suspects on the basis of the crimes they are believed to have committed, the concept of due process is flexible enough to support a prohibition on the use of deadly force against persons suspected only of minor offenses. Nevertheless, due process itself provides no principled basis for determining what crimes are sufficiently serious to justify resort to a deadly weapon against a fleeing suspect. This gap can be filled by drawing an analogy to a recent Supreme Court decision establishing that the death penalty constitutes disproportionate punishment for all but the most serious crimes. A total of 223 footnotes are listed. (Author abstract modified)