Cross-Examination: Basis of knowledge

A few days ago, we discussed cross examination with the goal of exposing bias.

Today, we’re going to discuss cross examination where we challenge the basis of the witness’s knowledge.

Witnesses will often confidently tell their stories on direct examination.

Generally, they have been prepared by opposing counsel and they know the questions they will be asked on direct. Their confidence is high, and their purpose is clear.

One way to shake that on cross examination is to slowly undermine their assumptions and basis for their knowledge or understanding of what happened.

Perhaps point out that someone had a better vantage point (ideally your own testifying witness).

Identify factors that could shake their confidence in what they perceived.

That could come in the form of limits on perception and memory such as:

1.      Duration of event (happened quickly)
2.      Environment (weather, noise, obstacles, lighting)
3.      Physical limitations (hearing, eyesight, tired, stress, limits on senses, distance, distractions)
4.      Judgment (no stopwatch, measuring tape, camera)
5.      Lack of knowledge (education, training, experience)
6.      Limits on memory (length of time since event, event not written or recorded, interim events)

Question their judgment or ability to understand what they experienced.

During the sentencing phase of a federal death penalty trial I prosecuted, the defense called the jail chaplain to testify about the defendant’s efforts to help and minister to other inmates while awaiting trial. He made conclusions about the defendant’s character from those events.

During my cross examination, I challenged the basis for his understanding.

I asked him if he had been aware that at the same time the defendant was supposedly “ministering” to other inmates, he was also hatching a conspiracy to engage in a violent escape attempt? He said no.

I asked him if he was aware that some of the other inmates to whom the defendant was ministering actually became co-conspirators in the escape attempt in which guards were injured? He said no.

I asked him if he knew that the defendant was using the mail at the jail to order a “hit” on a co-defendant who testified against him? He said no.

Witness neutralized.

Enjoy the clip from the movie Caine Mutiny in which the cross examiner reveals the lack of a basis of knowledge of the witness.