Irony of the Day: Getting Credible Evidence from Criminals

For reason that are to my mind not that clear, we distrust the truthfulness of criminals, but most especially felons, those who have been convicted of serious crimes. "At common law a person who had been convicted of a felony was not competent to testify as a witness," a rule which was ultimately "rationalized on the [bald] basis that such a person was unworthy of belief." Green v. Bock Laundry, 490 U.S. 504, 511 (1989). Today, felons are competent to testify in court, but their credibility may be attacked on the stand, or "impeached," simply on the ground that they are a felon, without regard to whether or not the crime didn't "involv[e] dishonesty." Id. at 509 (construing  Fed. R. Evid. 609(a)); id. at 532 (Blackmun, J dissenting) (saying the rule in 609(a) was founded on the determination that "any felony conviction has sufficient relevance to a witness' credibility to be admitted, even if the felony had nothing directly to do with truthfulness or honesty").

Isn't it perfectly rich, then, that so often, the only people that we can actually get to give evidence to convict of crimes are the criminals themselves? The plurality opinion in United States v. Mandujano, 425 U.S. 564, 573-74 (1976) collects quotes and sources:

"Since the subject matter of the inquiry is crime, and often organized, systematic crime—as is true with drug traffic—it is unrealistic to assume that all of the witnesses capable of providing useful information will be pristine pillars of the community untainted by criminality.

The Court has never ignored this reality of law enforcement. Speaking for the Court in Kastigar v. United States, MR. JUSTICE POWELL said: ‘[M]any offenses are of such a character that the only persons capable of giving useful testimony are those implicated in the crime.’ 406 U. S., at 446.

MR. JUSTICE WHITE made a similar observation in the context of a state investigation: ‘[T]he very fact that a witness is called . . . is likely to be based upon knowledge, or at least a suspicion based on some information, that the witness is implicated in illegal activities….’ Murphy v. Waterfront Comm'n, 378 U. S. 52, 102 (1964) (concurring opinion).

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There is nothing new about the Court's recognition of this reality.... In one of the early cases dealing with the Fifth Amendment privilege, the Court observed: ‘[I]t is only from the mouths of those having knowledge of the [unlawful conduct] that the facts can be ascertained.’ Brown v. Walker, 161 U. S. 591, 610 (1896).