Final answer:
Circumstantial evidence and expert testimony are the most useful in a negligence case when the plaintiff lacks direct evidence. Eyewitness testimony is less reliable due to potential for suggestibility and memory flaws. Hearsay is generally inadmissible in court.
Step-by-step explanation:
When a plaintiff sues in negligence without direct proof that the defendant behaved unreasonably, the use of circumstantial evidence is often crucial in establishing a case. While eyewitness testimony can be influential, courts are increasingly aware of its potential unreliability due to factors such as suggestibility and memory flaws. Expert opinion can be valuable, especially if it is from a credible source that reflects a consensus among experts in the relevant field, is unbiased, and well-informed. However, hearsay is generally not admissible in court because it is not given under oath and is not subject to cross-examination, with few exceptions like an admission of guilt or a dying declaration.
Jurors tend to put substantial weight on eyewitness testimony, despite its fallibility. Awareness of the problems associated with eyewitness identification has led to changes in law enforcement and judicial practices, including neutral interviewing techniques and blind lineups to reduce suggestibility, as well as judicial instructions to jurors about the risks of misidentification. In cases where a plaintiff lacks direct evidence of negligence, the combination of circumstantial evidence and expert testimony that meets the criteria for reliability is likely to offer the most support to their case.