General
Q: What is the difference between character evidence and propensity evidence?
A: Character evidence is any evidence about a person’s traits. Propensity evidence is using that trait to prove they acted in conformity with it on the occasion in question. 404(a) bars propensity use unless an exception applies
Q: Why does asserting entrapment make prior bad acts admissible?
A: Entrapment places defendant’s predisposition directly at issue. Predisposition = character, so 404(a) allows prior similar acts to rebut entrapment.
Defendant is charged with an armed robbery committed with a revolver. Prosecutor seeks to introduce evidence that police found three other revolvers in defendant’s closet to show he is “the type of person who likes guns.”
Answer: Inadmissible. Pure propensity.
(Not tied to the charged gun; no identity, knowledge, or opportunity purpose.)
Defendant is charged with hacking a corporation using a highly technical zero-day exploit. Prosecutor wants to introduce evidence that defendant taught a seminar the year before on exploiting the same vulnerability.
Answer: Admissible for knowledge.
Shows defendant had the rare skill needed; not offered to show he is “the type to hack.”
Q: When is character evidence admissible in a criminal case to show defendant acted a certain way?
A: Only when the defendant opens the door under 404(a)(2) or when character is an element of a defense (rare). Otherwise barred as propensity.
Q: When is character evidence admissible because character is an element of a claim or defense?
A: In civil cases like defamation (truth as defense), negligent entrustment (knowledge of incompetence), and when an employer justifies termination based on the employee’s character trait.
Defendant is charged with arson. The fire was started using a homemade device made from a wine bottle, motor oil, and a purple candle. Prosecutor seeks to introduce evidence that defendant committed a prior arson using an identical device.
Answer: Admissible for identity.
Highly distinctive M.O. → proper 404(b)(2) purpose; not propensity.
Defendant is charged with securities fraud involving fake “energy startup” investments. One year after the charged fraud, defendant ran a nearly identical scheme under a new company name.
Answer: Admissible to show intent.
Even later acts can be used to rebut “I was surprised like everyone else.”
Q: When similar-acts evidence is used to show identity, what makes it admissible?
A: The prior act must have distinctive, signature-like features tying it specifically to the defendant — not just showing “type of person.”
Q: Why can similar prior fraud schemes be admitted to show intent?
A: Because when defendant claims innocent mistake (“I was surprised like everyone else”), prior similar schemes rebut that and show knowledge & intent.
Plaintiff sues a delivery company for negligent entrustment after its driver caused a crash. Plaintiff seeks to introduce evidence the driver had four prior speeding citations that the employer knew about.
Answer: Admissible for knowledge (employer’s notice).
Not admissible to show the driver has a “bad driving character," but relevant to employer’s knowledge.
Defendant is charged with receiving stolen laptops. Prosecutor offers evidence that two years earlier defendant was caught buying electronics with serial numbers scratched off.
Answer: Admissible for knowledge.
Shows awareness of how stolen goods are typically disguised; not admissible for propensity.
Q: When is prior-acts evidence admissible to prove knowledge?
A: When the prior act would have put defendant on notice, such that the fact pattern shows familiarity or awareness (e.g., prior DUI classes → awareness of danger; prior stolen goods with scratched serial numbers → knowledge goods were stolen).
Q: Why is evidence of prior violence admissible in a stalking prosecution?
A: Prior violence is direct proof of an element — that the defendant put the victim in sustained fear — AND it shows intent. Not used for propensity.
Defendant physician is charged with illegal distribution of opioids. He claims entrapment. Prosecutor seeks evidence of three prior unlawful prescriptions.
Answer: Admissible. Entrapment places predisposition at issue; 404(a) allows propensity evidence in this limited context.
Defendant is charged with insurance fraud for claiming his home burned down accidentally. Prosecutor wants evidence that defendant’s previous two homes also burned down due to “accidents.”
Answer: Admissible for absence of mistake/lack of accident.
Multiple similar “accidents” allow an inference of intentional conduct.
Q: When is prior misconduct admissible to show absence of mistake or lack of accident?
A: When repeated similar incidents make defendant’s “accident” explanation implausible (e.g., four prior house fires before an alleged accidental arson).
Q: When the defendant claims self-defense, can prosecutor use prior acts of defendant’s violence against others?
A: No. Character for violence is not an element of self-defense, and unless tied to motive or the same victim or event, it is impermissible propensity.
Politician sues bestselling author for libel for calling her “chronically dishonest.” Author seeks to introduce evidence of the politician’s numerous documented lies in public office.
Answer: Admissible. Character for untruthfulness is an element (truth as a defense).
Defendant is charged with assault and claims self-defense. Prosecutor wants evidence defendant previously assaulted three strangers in bar fights.
Answer: Inadmissible. Pure propensity.
Defendant’s violent character is not an element of self-defense; prior acts not tied to the victim or the event.