The impeachment of witnesses and the examination of hostile witnesses in criminal cases is
governed by Rule 238.
Rule 433.Impeachment of Witnesses; Hostile Witnesses
Article IV. Rules on Criminal Proceedings in the Trial Court · Part C. Trials · Last amended 1982 · Last verified July 20, 2026
In one sentenceRule 433 applies the civil rule on impeaching witnesses to criminal cases, letting any party attack a witness's credibility, even a witness it called itself, and question a hostile witness as if on cross-examination.
Full Text of Ill. S. Ct. R. 433
Plain-English Summary
Rule 433 borrows its standard from Rule 238, the civil impeachment rule, and applies it to criminal trials. Under that rule, any party can attack a witness's credibility, including the party that called the witness in the first place; a lawyer isn't stuck vouching for the honesty of every witness on the stand.
The rule also addresses hostile or unwilling witnesses. If the court finds a witness fits that description, the party who called the witness can question that witness as if conducting a cross-examination, using leading questions rather than being limited to open-ended ones.
Frequently Asked Questions
Can a party impeach the credibility of a witness it called itself?
Yes. Rule 433 lets any party attack a witness's credibility, including the party that called the witness.
What makes a witness 'hostile' under this rule?
The rule leaves that determination to the trial court, which decides whether a witness is hostile or unwilling based on the witness's conduct and answers.
What does it mean to question a witness 'as if under cross-examination'?
It means the questioning party can use leading questions, the same technique normally reserved for cross-examining the other side's witnesses.
Does Rule 433 create new rules just for criminal trials?
No. It applies Rule 238, the civil rule on impeachment and hostile witnesses, to criminal cases.
Why would a prosecutor or defense attorney need to impeach their own witness?
A witness may testify unexpectedly or unfavorably, and this rule lets the calling party challenge that testimony's credibility rather than accept it without question.
Amendment History
Adopted September 29, 1978, effective November 1, 1978; amended February 19, 1982, effective April 1, 1982.
Source & verification. Rule text, official Committee Comments, and
amendment history are reproduced verbatim from the Illinois Supreme Court Rules,
promulgated by the Supreme Court of Illinois. Last verified July 20, 2026.
· Official source
Also known as: impeaching witness criminal trial illinoishostile witness rule criminal caseattack own witness credibilitycross examine own witness ruleimpeachment of witnesses illinois