Question

Question 5. A person is murdered on a deserted island. There are only 10 individuals who may have committed the murder. Detectives are testing the DNA found on the murder weapon for a particular genotype, which occurs with a frequency of 5% in the population. Joe Bloggs is the first suspect to be tested and he has tested positive for the genotype. What is the probability that Joe Bloggs is guilty of the murder?

Assume the DNA on the weapon belongs to the murderer, not the victim.

Answer 1

Probability that Joe Bloggs is guilty of the murder = Probability that Joe Bloggs is one among the 10 individuals who may have committed the murder X the DNA on the weapon belongs to him

= (1/10) X (5/100)

= 0.005

So,

Answer is:

0.005