By Dr. Ken Broda-Bahm:
Late last week, as large crowds in Ferguson continued to protest the police shooting of the 18-year-old unarmed Michael Brown, Police Chief Thomas Jackson made two announcements. One, he released the name of the officer involved (Darren Wilson) after it was already released by the hacker goup Anonymous. And two, he released surveillance footage showing what appears to be Brown stealing a box of cigars and shoving a store clerk. At first, the new disclosure seemed to change the narrative, raising the question of whether Officer Wilson was following up on the theft before the situation turned fatal. Hours later, however, the police chief clarified that at the time of the stop, the officer did not know that Brown was a suspect in a recent robbery. The reaction from Brown’s family and other protesters was swift: By releasing a questionable video, the Ferguson Police Department was trying to assassinate the man’s character, blame the victim, and otherwise distract media and public attention from its own actions on that day.
This backlash based on the perception of irrelevant personal attack has its parallel in court: One side trots out a fact that they believe will dramatically reframe the story, and instead that fact ends up blowing up in its face and raising questions about its own motives and character. This negative evidence may have some arguable relevance, and may even get past the other side’s objections, but the jury still sees it as a distraction and an attempt to manipulate. The field of informal logic calls this the ad hominem fallacy, and empirical research shows that the approach is condemned when it is recognized. But there’s the rub: It is often missed when a personal attack is seen as a relevant argument. The question of whether a character attack is relevant or irrelevant is often ambiguous – and this is nowhere more true than in law where fact finders are asked to evaluate the credibility of parties and witnesses. Because character can matter in this setting, this post takes a look at the ad hominem – it’s meaning and effectiveness – as well as some practical ideas on how it's defended and attacked in trial.