EVIDENCE

Testimonial Evidence A statement made under oath. = direct evidence = prima facie evidence Evidence that would, if uncontested, establish a fact or raise a presumption of a fact

Testimonial Evidence: Eyewitness Accounts Juries are heavily influenced by them

Testimonial Evidence: Eyewitness Accounts Juries are heavily influenced by them Accuracy problems

Physical Evidence Any material or object. LIST: More reliable than testimonial evidence

Physical Evidence Direct Physical Evidence can prove an event. E.g., Possession of a controlled substance Alcohol content of blood Indirect Physical Evidence supports an event. E.g., Presence of a blond hair A skid mark

Physical Evidence When possible, a questioned sample should be collected with a control sample. Samples should be taken from

Physical Evidence may have Class Characteristics or Individual Characteristics

Probative Value of Physical Evidence PROBATIVE = the ability of evidence to prove something or supply evidence that is material to a crime If the physical evidence is individual, there should be no question. If the physical evidence is only class, then the more samples of class evidence you have, the better the probative value.

Probative Value follows the Product Rule Probability X probability X probability … = probability of all together The more pieces of class evidence that you have, the more likely it is that only one person or object matches all of those pieces of class evidence.

Probative Value of Physical Evidence A young person was seen leaving the high school pit area after having been near a car with a broken window. The car’s CD player was missing. The suspect was identified as having light brown hair and wearing a light colored T-shirt, blue jeans, and dark-colored athletic shoes. In our school of 1400 students, how common are these characteristics?

Probative Value light brown hair light colored T-shirt blue jeans % in Class Probability in School light brown hair light colored T-shirt blue jeans dark-colored athletic shoes