Most, if not all, jurisdictions have no minimum age requirement in order for a child to be permitted to testify in court. Instead, judges are given discretion to determine whether a child is competent to testify.
In most jurisdictions, judges look at the issue from two perspectives:
- At the time of the event that the child will testify about, did the child have the ability to observe and remember the event? and
- At the time of testimony, does the child has the ability to remember the past event and accurately narrate the facts surrounding it?
If the answer to these two questions is “yes,” then the child is considered competent to testify. Using this standard, in Texas courts, as in other state and federal courts, children as young as four years of age have been permitted to testify.
A child doesn’t have to understand what the formal oath means in order to testify, either. In fact, it is not uncommon for courts to dispense with administering a formal oath to a child witness. Instead, the judge will determine if the child understands the need to be truthful, and, if so, then he or she will impress upon the child the need to be truthful in words that the child can understand. That admonishment will suffice in lieu of a formal oath.
For a more in-depth look at witness competency in Texas civil courts, go to: http://judgebonniesudderth.wordpress.com/2011/10/22/
— Bonnie Sudderth, Judge of the 352nd District Court of Tarrant County, Texas