What do you think of a modification of the exclusionary rule to incorporate qualified immunity principles. Currently, at least outside of the search warrant context, a "reasonable mistake" results in suppression of evidence in a criminal case, but the same mistake will not result in civil liability but dismissal on grounds of qualified immunity. Why not work the exclusionary rule that way? At a suppression hearing there must be causation (Hudson v Michigan) and then apply the qualified immunity standard---clearly established constitutional principle, and "unreasonable" mistake/violation. If not clearly established, reasonable mistake, or no causal connection, no suppression.

Extending the Leon rule to warrantless searches is something that has been kicked around for a long time. It would be a substantial overruling of precedent. I doubt the Court will go for in the foreseeable future.

I don't quite follow your argument that there is no causal connection in this situation.

I'm sorry I wasn't clear. I wasn't suggesting causation was absent in THIS situation, but suggesting a general rule for application of the exclusionary rule: first, is there a causal connection between the "wrongdoing" and the discovered evidence, second, if so, was the police conduct "reasonable" as understood in the qualified immunity situation (including that the "right" involved is clearly established), and I should add that third, does any exception to application of the exclusionary rule exist under the facts (inevitable discovery, independent source, purged taint, etc).

I agree that this would be a substantial overruling of precedent, and highly unlikely---so would an overruling of Mapp, and a decision not to apply it here if a 4th Amendment violation is found.

I think there is no 4th Amendment violation. I think Professor Kerr would find a violation in the following situation, which I find odd, if so. Say a state decides to amend its state constitution to provide a requirement for clear and convincing evidence for arrest, defined as meaning more than probable cause, and an arrest occurs which, while based on probable cause, is not based on clear and convincing evidence. Under Professor Kerr's analysis this is a violation of the 4th Amendment. And if the state said "but we do not apply the exclusionary rule to arrests based on probable cause but made in violation of the state constitution because not on clear and convincing evidence" a federal court would have to apply it anyway---to a probable-cause based arrest---because, since made in violation of state law, it is a violation of the 4th Amendment. This result seems to me to follow from Professor Kerr's view, and seems highly suspect to me.

Thanks for the response.