Would a confession obtained via Wonder Woman's Magic Lasso be admissible in US court, or any court?

Question

There's a scene in Justice League (the movie from 2017) where a policewoman is taking down the stories of three criminals who are wrapped in in Wonder Woman's magic Lasso.

The Lasso does a couple of things:

• Anything anyone who is touching the lasso says is true.
• It compels anyone touching the lasso to speak.
• And it also seems to compel this speech to be relevant. (Isn't magic useful?)

So a person bound by the lasso can't stay silent, or go on a rant about how Superman is wearing his underwear on the outside.

It seems to me that this sort of thing violates a person's 5th amendment right to stay silent. However, this question (ironically about masked vigilantes), asserts that a person's 4th amendment rights cannot in general be violated by a private citizen.

It seems to me that this should also apply to the 5th amendment, and I would find it hard to believe that Wonder Woman would be described as anything other than a private citizen.

Is the confession under the lasso admissible, or is it a violation of 5th amendment rights?

I'm definitely interested in US jurisdictions, but if you live somewhere else, I'd be interested to hear how the issue would be handled there.

EDIT:

As suggested by user6276 in the comments, it's quite possible that Wonder Woman is a deputized in some fashion, since she has various special immunities. It seems to me that if this is the case then the confession could not possibly be admitted (as a violation of 5th amendment rights). Feel free to let me know if that's wrong.

Answer 1

The Fifth Amendment only protects you against being compelled to testify by the government. So unless Wonder Woman is acting on behalf of the government, information obtained through the use of the Golden Lasso is admissible.

The question about whether she has been "deputized," is not the right one. Rather, the question is whether she is a "state actor." The answer to such a question is not always clear, as courts may ask a variety of questions to reach it: Is the actor paid by the government? Directed by the government? Assisted by the government? Acting under some power established by law? Also, is it "fair" to attribute that actor's actions to the government? Lugar v. Edmondson Oil Co., 457 U. S. 936 (1982).

Undoubtedly, there are occasions in Wonder Woman's history where she has worked closely enough with the police that a Golden Lasso confession would be inadmissible. And there are many times where she was working so independently that a Golden Lasso confession would be plainly admissible.

I don't remember the exact circumstances of the confessions you're talking about, but if they were from the "small group of reactionary terrorists" I remember from the beginning of the film, I can't think of any basis for excluding their confessions. Wonder Woman came on scene independently, took control and subdued the suspects without any police direction or assistance. Unless the police later asked her to assist with the interrogations, those confessions could not be "fairly attributed" to the government.

(All of this is of course ignoring the fact that the crime and confessions occurred outside of the United States and are therefore not covered by the Fifth Amendment.)