A crime is committed by one of two suspects, A and B. Initially, there is equal evidence against both of the suspects. After further investigation, it is determined that the guilty party has a blood type found in only 10% of the population at large. Suspect A does have this blood type; the blood type of Suspect B is unknown.
Define the following 3 events A, M and C.
A: "A is guilty" (Thus ° denotes "B is guilty')
M: "A’s blood type matches that of the guilty party"
C: "B's blood type matches that of the guilty party"
A. The police reported that suspect A is not a relative of suspect B. Is it reasonable to set P( MA)=P(C|A)=10%? Why?
B. Assume that P(MAC)=P(C|A)=10%. Given the information from the further investigation of the crime scene, what is the probability that A is the guilty party?
C. Assume that P( MA)=P(C/A)=10%. Given the information from the further investigation of the crime scene, what is the probability that B’s blood type matches that of the guilty party?