Constitutional limitations on things like censorship, discrimination, and search and seizure do not apply to private individuals but rather to the federal government and, in some cases, to the states. (The Thirteenth Amendment is a rare exception that applies to individuals). As a result, evidence that a superhero obtains by breaking into a villain’s headquarters is admissible even though it was obtained illegally. See, Burdeau v. McDowell, 256 U.S. 465 (1921). And since it doesn’t invoke the fruit of the poisonous tree doctrine, any additional evidence obtained via the original evidence would also be admissible.
But what about superheroes like Batman who work in close cooperation with the police? Could they fairly be described as state actors, thus triggering a whole spate of Constitutional protections? I think the answer may be yes.
In Lugar v. Edmondson Oil Co. the Supreme Court gave a two-part test for whether the conduct of a private party could be fairly attributable to a state, thus implying state action:
First, the deprivation must be caused by the exercise of some right or privilege created by the State or by a rule of conduct imposed by the State or by a person for whom the State is responsible….Second, the party charged with the deprivation must be a person who may fairly be said to be a state actor. This may be because he is a state official, because he has acted together with or has obtained significant aid from state officials, or because his conduct is otherwise chargeable to the State. Lugar v. Edmondson Oil Co., 457 U.S. 922, 937 (1982).
In Batman’s case, Commissioner Gordon is certainly a person for whom the State is responsible, and Batman often acts together with Gordon and obtains significant aid from Gordon in the form of information and evidence. Batman’s conduct is also otherwise chargeable to the State because the Gotham Police Department has worked with Batman on numerous occasions (and thus knows his methods) and operates the Bat Signal, expressly invoking Batman’s assistance in a traditionally public function. This suggests state action under the public function theory: “when private individuals or groups are endowed by the State with powers or functions governmental in nature, they become agencies or instrumentalities of the State and subject to its constitutional limitations.” Evans v. Newton, 382 U.S. 296, 299 (1966).
In the real world, this would cause significant problems for Batman and Gotham. Batman’s rough and tumble style would lead to a rash of Section 1983 claims for damages and probably also for an injunction against Batman’s future cooperation in police investigations. As discussed earlier, most evidence that Batman collects would be inadmissible, and police use of that evidence might bar the use of additional evidence collected during a subsequent police investigation.
Now, clearly none of this is the case, so there are three possibilities. Either all of the criminals in Gotham have incompetent attorneys, the state action doctrine in the DC universe is weaker than it is in the real world, or Gordon has actually managed to keep his reliance on Batman a secret. I’m going to opt for the second explanation. Superheroes like Batman are simply too effective for a court to shackle them with the Constitutional limitations of the state, especially with supervillains running around. Perhaps the DC universe courts have developed a public emergency or necessity exception to the state action doctrine whereby private individuals pressed into public service in an emergency are not held to the same standards as ordinary state actors.