(concurring) :
I concur in the result, but wish to set out my understanding of what the court does today.
In future cases of this sort the issue of scope of authority will not be relevant inasmuch as we now hold that federal law enforcement agents are not immune even if acting within their powers. The trial judge will pass on the sufficiency of the complaint just as he would in a section 1983 action against a state police officer. If the complaint states a cause of action and the plaintiff adduces substantiating proof, the defendant will have to disprove the allegation that he acted without probable cause, or show that, in any event, he acted in good faith and with a reasonable belief in the validity of the arrest and search.
Ordinarily when a suit of this type is brought a court will already have determined that there was no probable cause for the arrest and search complained of. Nevertheless the agent has a complete defense if he can convince the trier of the fact that he acted in good faith and that it was reasonable for him to have believed that the arrest and search were lawful. Thus there are two standards to be considered. The first is what constitutes reasonableness for purposes of defining probable cause under the fourth amendment for the protection of citizens against governmental overreaching. The other standard is the less stringent *1349reasonable man standard of the tort action against government agents. This second and lesser standard is appropriate because, in many cases, federal officers cannot be expected to predict what federal judges frequently have considerable difficulty in deciding and about which they frequently differ among themselves. It would be contrary to the public interest if federal officers were held to a probable cause standard as in many cases they would fail to act for fear of guessing wrong. Consequently the law ought to, and does, protect government agents if they act in good faith and with a reasonable belief in the validity of the ari'est and search.