Final answer:
Delayed questioning after the event is most likely to decrease the accuracy of Vera and Xavier's recounting of the crime.
Step-by-step explanation:
According to research by Garry, French, Kinzett, & Mori (2008), delayed questioning after the event is most likely to decrease the accuracy of Vera and Xavier's recounting of the crime. When there is a delay between the event and the questioning, witnesses' memories can become distorted or influenced by external factors, leading to inaccuracies in their recollection. This is because memory is fragile and can be easily influenced by suggestive information. For example, post-event information or misinformation can change the details of the original memory, causing witnesses to provide inaccurate or false accounts.