When presented with circumstantial evidence and no eyewitnesses to a robbery-murder case, Elizabeth Loftus found in her study that 18 percent of her participants voted to convict the suspect. Presented with the same information plus one eyewitness, percent of participants voted to convict.

Seventy-two.

Explanation:

Elizabeth Lotus is an American psychologist who has published a series of studies about the unreliability and erring tendencies of eyewitness testimonies.Elizabeth spent an a lot of effort in understanding the accuracy of memories and how the brain can create false memories by repression and manipulation.In one of her ground breaking study, Elizabeth found that only 18 percent of her participants voted to convict the suspect when they were presented with circumstantial evidence and no eyewitnesses to a robbery-murder case.However, seventy-two percent of participants voted to convict the the same suspect when they were presented with circumstantial evidence and one eyewitness.According to her, one eyewitness can provide a compelling testimony to manipulate the minds of the people. Therefore, it is important for lawyers or anyone to understand the unreliability and erring tendencies of eyewitness testimonies.