Basic Competency (FRE 601) .
A witness is objected to because she is a practicing Mormon. Is she competent to testify?
Yes. Religious belief cannot render a witness incompetent.
A 3-year-old child is called to testify and the opposing party objects solely on the ground of age. Competent?
Yes. Age alone is not a basis for incompetency.
A victim’s testimony is refreshed through hypnosis. Admissible?
Typically excluded—hypnotically refreshed testimony is often deemed incompetent unless constitutional rights are implicated.
A lawyer representing plaintiff is called to testify about a past meeting. Is the lawyer incompetent?
No. Lawyers are competent witnesses; issues relate to disqualification, not competency.
A juror wants to testify that deliberations included discussion of a Buzzfeed article about the case. Admissible?
Yes—this is extraneous prejudicial information.
A husband objects to his sister-in-law’s testimony because she stands to gain a Mustang if his wife wins the divorce. Does interest defeat competency?
No. Interest goes to bias, not competency.
A child believes guinea pigs can fly but agrees to tell the truth. Competent?
Yes. Flights of imagination do not defeat competency if the child understands truth vs. lies.
A defendant’s hypnotically refreshed testimony is offered. Admissible?
Yes. Under Rock v. Arkansas, the defendant has a right to testify even if refreshed by hypnosis.
A trial judge from a prior case is called to testify about what was decided previously. Competent?
Yes, because it is not the same proceeding; FRE 605 applies only to the presiding judge.
A juror wants to testify that defendant’s brother glared at her and intimidated her outside the courtroom. Admissible?
Yes—this is an “outside influence.”
A witness is a heavy marijuana user and had just left a dispensary before observing an accident. Is he permanently incompetent?
No. Drug intoxication affects perception but not permanent testimonial capacity.
A child refuses a formal oath but demonstrates she can identify truth and promises to tell the truth. Competent?
Yes. Understanding the moral duty to tell the truth is sufficient.
A witness suffers from mental illness that impairs perception, recall, and narration. Competent?
No—if impairment destroys basic testimonial faculties, competence fails.
A stepson attempts to testify to the deceased’s statements about being coerced into signing a will. The daughter invokes the state’s Dead Man’s Statute. Admissible?
Possibly excluded; federal court must apply the state’s Dead Man’s Statute in civil cases.
A juror testifies that another juror said, “Scientologists can’t be trusted.” Admissible?
Unclear—religious bias may not qualify under current Pena-Rodriguez (which is limited to racial bias).
A witness has dementia but can still recall events with some detail. Competent or incompetent?
Competent. Mental illness alone does not render a witness incompetent.
A 5-year-old insists the “Power of Grayskull” makes him tell the truth. Does this satisfy oath requirements?
Yes. Any genuine commitment to truthfulness satisfies FRE 603.
A witness testifies through a translator who did not take an oath. Is the testimony admissible upon objection?
No. An interpreter must take an oath to be competent.
Are people challenging wills automatically incompetent?
No. Dead Man’s Statutes vary by state; there is no per se federal incompetency rule.
A juror made a mistake writing the damages amount on the verdict form. Can a juror testify to correct it?
Yes—clerical mistakes are an exception to 606(b).
A witness with dementia cannot recall anything that happened more than 10 minutes ago. Competent?
No. A lack of ability to recall is a valid basis to find a witness incompetent.
Are children under 4 per se incompetent?
No. FRE 601 presumes competency regardless of age.
Same oath-less interpreter, but no objection is raised. Is the translated testimony likely allowed?
Yes, absent objection and absent evidence of inaccuracy.
Who is automatically incompetent to testify under the Federal Rules?
The sitting trial judge and sitting jurors in the same case.
Jurors reached a damages figure by submitting numbers and averaging them. Can jurors testify to this?
No—this reveals jurors’ mental processes during deliberations.