Admissibility of Expert Testimony

Abstract

These cases illustrate some of the dilemmas encountered by courts when deciding who is an expert and to what can an expert testify? In the first example, the court must decide if the eye witness’s testimony was reliable. Would a psychologist’s testimony about the research on accuracy of eyewitness memory help the court do its job? In the second example, the court has to decide if scientific testimony by the general expert who did not examine Tate would provide information in addition to the experts who examined him by each side, to assist the jury in making the decision as to whether he had the capability to form the same intent as an adult. In the third example, the court must decide if the fact that Sara demonstrated characteristics of Rape Trauma Syndrome would prove that James had actually raped her?

Jane Smith was standing on a busy street corner and observed a truck run a red light and collided with two different automobiles. The red one jumped the curb and hit several pedestrians. The pedestrians filed a lawsuit against the truck driver and wanted to call Jane as a witness to the accident. The defense protested and wanted to call a psychologist to testify about the unreliability of Jane’s memory of the events. Should the defense psychologist be allowed to testify?

Lionel Tate was 12 years old when he wrestled to death a 6-year-old girl whom his mother was babysitting. He was arrested and charged with her murder and the state attorney waived his prosecution into adult court. Tate’s lawyers wanted to put on psychologists to testify that the research demonstrates that 12-year-old children in general do not have the mental capability for forming the same intent to kill as an adult. Other psychologists who had actually examined Tate were prepared to testify for both sides—each side putting forth the viewpoint supporting their own position. Should the judge allow the research psychologist to testify about science in general without himself having examined Lionel Tate?

Sara went out on a date with James and when they returned he invited her into his apartment for a drink. She accepted his invitation as he had been a perfect gentleman during the rest of the evening. Within a short time after getting there, James began kissing her. Sara was relaxed and enjoying the attention until his kisses became more insistent and rough. She became frightened of the look in James’ eyes when she asked him to stop and he didn’t comply. She began crying and begged him to stop and take her home. He refused and raped her. Sara was so upset that she reported the sexual assault to the police. James admitted having a sexual encounter with Sara that night but insisted it was mutually consensual. The state attorney wants to call as a witness a psychologist who will testify that Sara demonstrates characteristics of Rape Trauma Syndrome and therefore, this could not have been a consensual encounter for her. Should the court allow this psychologist to testify?