It seems to me that when someone is offered immunity to testify against their friend-in-crime, they could simply discredit themselves with something along the lines of:

were you paid for your testimony?

yes, they offered me freedom

would you have testified the same regardless of guilt?


then how can we believe anything you said?

you can't

Maybe I am missing something, but it seems pretty broken to me...

  • You are probably right to see a problem in the immunity/plea bargain system as it is used today in many countries, but using the label paid testimony means using the literal, present-day meaning of words for an ancient institution. Queen's or king's witnesses have been used for centuries, and many legal systems recognize reduced sentences in exchange for a credible admission of guilt (as the first step towards repentance and reform).
    – o.m.
    Commented Nov 23, 2021 at 16:49
  • 1
    Worth noting that "paid testimony" is not inherently inadmissible. Most expert testimony is paid but still admissible and payment of reasonable expenses and inconvenience of a lay witness is not forbidden either. The notion that payment for testimony is forbidden appears to be a mistaken premise of the question. Payment to lie is illegal. Payment to testify is not.
    – ohwilleke
    Commented Nov 23, 2021 at 21:20

2 Answers 2


This is one of the things that the Prosecution is required to inform the defense of under Brady Disclosure and the Defense may raise issue with the testimony being less than reliable in part because the witness is benefiting from a quid pro quo for testimonial evidence. Brady Disclosure gets its name from the landmark SCOTUS case Brady v. Maryland which ruled that it is a due process violation for the prosecution not to turn over all evidence collected INCLUDING exculpatory evidence (i.e. evidence that helps show the defendant's innocence as opposed to inculpatory evidence, which shows the defendant's guilt.).

This is also to the Prosecution's interest because the prosecutor is not interested in convicting people but by discovering the truth as to what happened. And because a conviction should only happen when the truth is so compelling that it is beyond a reasonable doubt, the prosecution's evidence is scrutinized much more rigorously than the defendant's. After all, if an innocent person is found legally guilty of a crime, all that does is let the guilty party walk free... and the public will be unwilling to look for who really did it because it's convinced they got the right man.

  • In other words, testimony can be impeached on these grounds at trial (and almost always is impeached at trial on these grounds) but it is a question of credibility for the jury to decide and not a question of admissibility.
    – ohwilleke
    Commented Nov 23, 2021 at 21:11

when immunity is offered in exchange for testimony, how is that not paid testimony and thus ignored?

It's a matter of prosecutorial efficiency, provided that the testimony at issue is truthful.

Immunity agreements with key witnesses contribute to a more efficient allocation of the limited resources the prosecutor has for prosecuting criminal activity. See Plaster v. U.S., 789 F.2d 289, 293 (1986) ("The government alone makes a decision not to prosecute in exchange for testimony which will, hopefully, lead to a greater number of indictments or convictions"). See also State v. Avila, 320 So.3d 456, 460 (2021) ("[immunity] agreements are not only constitutionally-permissible, but have also been heralded as essential to the proper functioning of our justice system", citing cases).

The dialogue you sketch mischaracterizes how testimony would develop. No reasonable witness would admit his testimony is independent of the defendant's actual guilt. That approach by the witness would nullify the immunity agreement because the purpose of testimony is to disclose the truth, and the witness's blatant admission hinders the jury's task of assessing credibility.

  • "That approach... would nullify the immunity agreement" Source? I am presuming that the questioner of the above line of questioning would be a defense attorney; While it may invalidate a plea deal, I was under the impression an immunity agreement (to waive 5th amendment rights not to to testify against oneself) would have Constitutional import, and not be revokable simply as the prosecutor doesn't like what the witness had to say...wouldn't the prosecutor have to prove that "would you have testified the same regardless of guilt" is false?
    – sharur
    Commented Nov 23, 2021 at 16:37
  • 1
    @sharur "Source?" See Avila at 460 ("[t]he validity of an agreement not to prosecute is generally determined under contract principles"). "and not be revokable simply as the prosecutor doesn't like what the witness had to say". It's not whether or the prosecutor likes the testimony given. A witness answering as the OP sketches makes no sense. A witness's statement that actual guilt is irrelevant to his testimony reflects that the witness is not even taking seriously his oath about telling the truth. As such, that is witness's breach of contract. Commented Nov 23, 2021 at 16:55

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .