An man was found dead with knife wounds in the biggest family gathering in the world with 4,000 relatives partying in a mansion. The home was put under lockdown so that no guests will leave and fingerprint analysis of the murder weapon using a rapid test kit was positive on the 400th person tested. Assuming that there is only a 1 in 500 chance of a false positive result, what is the probability that this person is guilty? Select the correct answer below.