Current events in Boston raise the question of whether the Fourth Amendment allows the government to conduct house-to-house searches for an armed and dangerous suspect on the loose. Assume the police enter a home without consent searching for Dzhokhar Tsarnaev; does the entry violate the Fourth Amendment? The answer depends on whether such home entries are “reasonable” under the Fourth Amendment, which requires a case-by-case balancing of the government’s interest in making the searches and the scope of the privacy invasion. The constitutional question would seem to depend on whether the searches are reasonably limited in scope (such as limited to a specific geographic area), the dangerousness of the suspect (here, very high), and the strength of the government’s case that the suspect may be in the area and cannot be caught another way. Fortunately there aren’t a lot of cases on anything like we’re seeing in Boston, at least as far as I could find. The closest cases I know of involve roadblocks instead of home searches, which is in the ballpark of dragnet searches and seizures but not particularly close on the facts. See, e.g., City of Indianapolis v. Edmond, 531 U.S. 32 (2000) (noting in dicta that “the Fourth Amendment would almost certainly permit an appropriately tailored roadblock set up to thwart an imminent terrorist attack or to catch a dangerous criminal who is likely to flee by way of a particular route.”); United States v. Paetsch, — F.Supp.2d —-, 2012 WL 5213011 (D.Colo. 2012) (dragnet roadblock at intersection to catch bank robber held reasonable under the Fourth Amendment).

Note that caselaw on these sorts of facts are particularly unlikely for reasons beyond the fortunate rarity of their occurrence. The suspect won’t have Fourth Amendment standing to bring a suit or a motion to suppress to challenge a search of someone else’s house in which he was hiding. See Rakas v. Illinois, 439 U.S. 128 (1978). As a result, only the legitimate residents could bring such actions in a civil case. And if they did bring such suits, qualified immunity would bar recovery unless the violation was clearly established — which is unlikely here given the novelty of the facts.