Chapter 7

Competency and Credibility

Competency:• A witness is properly able to take the stand

and give testimony in court.

• Competency is the second test for the admissibility of evidence.

• Presumption: all witnesses, regardless of age, are presumed competent to testify.

• Burden of proof falls to the side opposing the witness (prosecution or defense) to prove incompetency.

Tests for Competency:

1) ability to observe & perceive.

2) ability to recall and narrate.

3) ability to understand the duty to tell the truth.Note: when challenged, determined through voir

dire examination (see text for examples).

Witnesses with Possible Competency Problems:

1) Young Children: in CA, a child of any age can testify. However, the younger the child, the more likely the child will be unable to meet the three prong test for competency.

2) Senility: of one’s mental faculties have deteriorated with age or disorder, i.e., senile dementia or Alzheimer’s disease, a person could be proven incompetent to testify.

CHILD WITNESS• child was an eyewitness

as he watched his mother being systematically tortured to death by his father.

• for two days, (d) repeatedly beat her with a golf club, baseball bat, a chunk of wood, and stabbed her with scissors.

CHILD WITNESS• 4 year old witnessed

his father stab an 18 year old photo booth employee to death during a robbery.

• “I saw him stick a knife into her stomach and she yelled very loud!”.

3) Physically Handicapped: a blind or deaf person is limited in the type of testimony that he/she can give.

4) Mental Defect or Disorder: persons who are mentally incapacitated or insane persons are not competent witnesses.

Note: a developmentally disabled person can be a competent witness if he/she can meet the 3 prong test.

5) Foreign Speaking Persons: may not be able to narrate in English. The law provides for the appointment of a qualified interpreter.

6) Hypnotized Persons: in CA, persons who have been hypnotized are incompetent to testify as to any information recalled during or after hypnosis.

Note: investigators can use facts recalled under hypnosis to investigate.

Credibility: is the weight given to witness testimony by the trier of fact (the believability of the testimony). CA Jury Instructions direct the trier of fact to weigh the credibility of a witness’s testimony according to:

The length of time the witness had to observe the alleged criminal act and suspect

The stress, if any, to which the witness was subject at the time of the observation (see text for more).

Impeachment: to attack the credibility of a witness. Accomplished either by:

Cross or re-cross examinationIntroduction of rebuttal evidence

Common Grounds for Impeachment:1.Physical / mental state of the witness:

affects the ability of a witness to accurately recall, communicate, etc.

2.Bias, Interest, or Other Motive: normally the witness testimony must be corroborated with other evidence.

Financial Interest: a witness may financially benefit from a guilty verdict.

Relationship to a Party in the Case: Family member, fellow gang member

Prior declarations of hostility by the witness

3. Character Evidence: general reputation (pro or con) for

truthfulness, honesty, etc. prior felony conviction involving moral

turpitude or willingness to do evil.

4. Manner of Testimony:

Prior inconsistent statements or testimony

Bias or demeanor of testimony towards the prosecution or defense

Admission of untruthfulness

Conduct of an investigation

Rehabilitation: to restore or bolster the credibility of a witness and it takes place either:

During redirect examination – by bringing in new facts or clarifying answers from previous testimony

By introducing corroborating evidence through another witness which reinforces prior testimony