Answer:
Confirmation bias.
Step-by-step explanation:
Confirmation bias is a type of cognitive bias, it is a person's tendency to favor information that confirms their assumptions, preconceptions or hypotheses, regardless of whether they are true or not. The bias interpretes more positively those facts that basically support previous opinions. It is a cognitive prejudice that encourages one to continue in accordance with beliefs in order to avoid contradicting oneself. Peter used this type of bias, he searched and considered more intensively and selectively the information that confirmed his statement to blame Bill. This confirmation bias happens due people already have preconceived ideas from the start and to confirm they tend to collect evidence and selectively recall information and interpret it as a whole in a biased way.