I've been thinking more about Virginia v. Moore, the Fourth Amendment case I have blogged a lot about in the last few weeks. Here's a question for those readers following the case: Am I right that under Virginia's theory of the case, federal agents could make arrests for violations of state law? Sure, the agents couldn't actually bring charges themselves: They would have to arrest the target, search him, and then let him go. But unless I'm missing something, it seems plausible to me that the state's theory would allow the federal agents to use this "catch and release" tactic. After all, the arrest would be based on probable cause to believe a crime has occurred. If probable cause is enough, then the arrest and subsequent search should be fully constitutional.

  Why does this matter, you wonder? Well, there are two reasons. First, I would think agents would have an incentive to use this catch and release tactic in some settings if it is permitted. For example, imagine an FBI agent is investigating a suspect for narcotics smuggling. He can just stop the suspect for driving 36 in a 35, arrest him for speeding under state law, and search him for evidence or drugs. If no evidence is discovered in the search, then the officers will just let the suspect go and plan on getting him next time. Under the state's theory, as I understand it, this is perfectly okay: The arrest is based on probable cause, and the search is incident to a valid arrest because the arrest is based on probable cause. On the other hand, if the FBI agent uncovers evidence of a federal offense during the search incident to arrest, he can either bring in the target into federal court on the basis of the new evidence or let him go and keep the evidence for later.

  The second reason is that the "catch and release" tactic would seem to be relevant under Justice Souter's reasoning in Atwater v. Lago Vista. Justice Souter invoked the notion that arrest powers would be subject to political checks by the sovereign that enacted the relevant law:

  So far as [arrests for minor offenses] might be thought to pose a threat to the probable-cause requirement, anyone arrested for a crime without formal process, whether for felony or misdemeanor, is entitled to a magistrate’s review of probable cause within 48 hours, County of Riverside v. McLaughlin, 500 U.S., at 55—58, and there is no reason to think the procedure in this case atypical in giving the suspect a prompt opportunity to request release, see Tex. Tran. Code Ann. §543.002 (1999) (persons arrested for traffic offenses to be taken “immediately” before a magistrate). Many jurisdictions, moreover, have chosen to impose more restrictive safeguards through statutes limiting warrantless arrests for minor offenses. . . . It is, in fact, only natural that States should resort to this sort of legislative regulation, for, as Atwater’s own amici emphasize, it is in the interest of the police to limit petty-offense arrests, which carry costs that are simply too great to incur without good reason. See Brief for Institute on Criminal Justice at the University of Minnesota Law School and Eleven Leading Experts on Law Enforcement and Corrections Administration and Policy as Amici Curiae 11 (the use of custodial arrests for minor offenses “[a]ctually [c]ontradicts [l]aw [e]nforcement [i]nterests”). . . .
  The upshot of all these influences, combined with the good sense (and, failing that, the political accountability) of most local lawmakers and law-enforcement officials, is a dearth of horribles demanding redress.

  If agents are permitted to use a catch-and-release tactic, using state criminal law and not being limited by any state law restrictions, then these checks would seem to go away. First, there would be no check by a magistrate, because the federal agents would never bring in the target. Second, the state law restrictions wouldn't apply to the federal officers. Third, there would be no great costs of the arrests, as there would be no cases processed in court and the suspect would be set free. And fourth, there would be little political check, as the agent isn't even an official of the state that enacted the crime (and good luck complaining to the FBI about your fully-constitutional-but-really-annoying temporary arrest).

  Off the top of my head, I gather that this would be okay under the state's theory of the case. After all, the agent would have probable cause to believe a crime had been committed, and that's enough. Am I wrong about this implication of the state's theory? Or perhaps Virginia (or the United States) would say that probable cause is enough only if the arresting officer is an agent of the sovereign that has prohibited the conduct?

  UPDATE: I substantially amended the post shortly after posting it. In ligt of that, I have deleted a few comments that addressed a part of the post that was only up for a few minutes. My apologies for the lost effort on the part of those commenters.