Explanation:
- Terry v. Ohio (1968): Established that police may conduct brief investigatory stops and limited frisks when they have “reasonable suspicion” of criminal activity based on specific and articulable facts. Terry balances individual liberty against public safety: a stop is constitutional under the Fourth Amendment if an objectively reasonable officer could suspect wrongdoing. (Terry v. Ohio, 392 U.S. 1 (1968).)
- Whren v. United States (1996): Held that an officer’s subjective motive for a traffic stop is irrelevant to Fourth Amendment legality so long as there is an objective justification (probable cause or reasonable suspicion) for the stop. Thus, constitutional review focuses on objective facts, not the officer’s intent. (Whren v. United States, 517 U.S. 806 (1996).)
- Equal Protection and Racial Profiling: Although Whren limits Fourth Amendment challenges based on officer motive, claims that stops are motivated by race can proceed under the Equal Protection Clause. To prevail, plaintiffs generally must show discriminatory intent or impact — a higher bar: evidence that race was the but-for cause of the stop or that a policy/practice produces racial disparities. The Court has recognized that race-based policing raises constitutional concerns and sometimes requires different legal frameworks than ordinary Fourth Amendment review. See, e.g., cases and discussions considering disparate-impact evidence and the need for proof of intentional discrimination (Washington v. Davis, 426 U.S. 229 (1976); Village of Arlington Heights v. Metropolitan Housing Dev. Corp., 429 U.S. 252 (1977)).
- Castro considerations (racial-profiling context): In litigation challenging policing practices, courts examine both Fourth Amendment reasonableness and equal protection by assessing patterns, statistical disparities, training/policy directives, and eyewitness or internal evidence showing discriminatory intent. "Castro" here refers to doctrinal approaches used to evaluate racial-profiling claims (e.g., looking to statistical proof and comparative evidence, plus direct proof of discriminatory intent). Courts may enjoin practices when plaintiffs show systemic, race-based policing or when policies foreseeably produce racial targeting.
Taken together: Terry sets the baseline for permissible stops; Whren confines Fourth Amendment inquiry to objective justification and not officer motive; equal protection doctrine preserves a remedy for race-based policing but requires proof of discriminatory intent or systematically disparate impact. In cases like recent litigation over LA immigration stops, courts must reconcile whether stops were objectively justified under Terry/Whren and whether evidence of racial profiling is sufficient under equal protection principles to forbid or restrain the practice.
References: Terry v. Ohio, 392 U.S. 1 (1968); Whren v. United States, 517 U.S. 806 (1996); Washington v. Davis, 426 U.S. 229 (1976); Village of Arlington Heights v. Metro. Hous. Dev. Corp., 429 U.S. 252 (1977).