They just can't testify because they would be considered incompetent.

And they don't have to swear on a bible or anything. They just have to affirm that they will swear to tell the truth and understand the criminal penalty of perjury.

The rules of evidence require that all witnesses must be "competent" to testify. This means they must be able to understand and communicate and take a sworn affirmation to tell the truth.

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Last Edited By: Lt Sara Gilbert Sep 27 10 3:08 PM. Edited 1 times.