Basic Trope: A witness called to the stand gives testimony harmful to the side that called them.
- Straight:
- Bob is on trial for robbing a bank, and calls Alice to testify as his alibi. She says that she saw him go into the bank at the time of the robbery.
- Alice gives a seemingly solid alibi, but upon cross-examination from the prosecution, she reveals she doesn't remember some key details about that day. This makes her validity as a witness come into question, and destroys Bill's defense.
- Exaggerated:
- Alice's testimony reveals that Bob is also responsible for half a dozen other bank robberies and two cold case murders.
- Alice is so uncertain about a hundred different details in the alibi that all she ends up being good for is as a character witness, and then she blurts out solid proof that Bob has the kind of character to commit the crime.
- Downplayed: Alice's testimony doesn't become evidence against Bob, but she's useless as an alibi.
- Justified:
- Alice knows that Bob is guilty, but lacks any other proof, so she lies to incriminate him.
- Alice initially planned on lying to cover for Bob's guilt, but he's such a jerk to her that she decides to tell the truth anyway.
- During cross examination, Alice continues to state she didn't see Bob anywhere near the robbery scene and remembers him coming home with dinner shortly after the robbery to the point she genuinely believes he couldn't have been nearby. The prosecution then calls out an exhibit, and Alice immediately identifies it as belonging to Bob... unaware it was left at the crime scene.
- Played for Laughs: While Alice is on the stand, Bob realizes his mistake and tries increasingly outlandish Unconventional Courtroom Tactics to stop her testimony.
- Bob asks Alice to tell the court that he is innocent of bank robbery. Alice, on the witness stand, angrily says she was caught with money matching the bank robbery money ''Bob'' paid her to lie with..
- Played for Drama: Alice lies her testimony to falsely incriminate Bob, and he has an Et Tu, Brute? moment when he realizes.
- Alice tells the courtroom that Bob is innocent, however the prosecution manages to get her to admit she was being blackmailed by Bob to stay quiet or he'd hurt her after the trial.
- Inverted: Alice ends up Taking the Heat and confesses to Bob's crimes on the stand.
- Subverted: Alice is found to be lying to falsely incriminate Bob, so she's charged with perjury and her testimony is stricken from the record.
- Double Subverted: Alice admits that she was bribed to falsely incriminate Bob... but it turns out that Bob was behind it, and he hoped news of her being bribed to lie would cause a mistrial.
- Deconstructed: Alice's testimony causes Bob to question his lawyer's competence, since a good lawyer thoroughly vets every witness they bring in.
- Averted: Alice gives a beneficial testimony that strengthens Bob's alibi.
- Defied:
- Just before Alice testifies, Bob learns that what she'll say will harm his case, so he has her pulled from the witness roster at the last minute.
- Bob and his lawyer thoroughly question Alice beforehand to make sure that her testimony will follow whatever narrative Bob needs to stay out of jail, and that there is nothing she could possibly say, omit, or imply that could be weaponized against him by the prosecution.
- Parodied:
- Alice's testimony implicates Bob in incredibly minor peccadillos that aren't crimes at all, like stealing his friend's lunch in 4th grade or refilling his drink without paying.
- Bob calls himself to the stand, and his own lawyer ends up inadvertently causing him to confess his guilt.
- Conversed: "You know that if you make me take the stand I may end up saying something that will screw you over, right?" "I'd rather go to Alcatraz for the things I actually did than for the crap Jack is trying to frame me for!"
