A body was found in a bag floating in a river by a fisherman. The preliminary investigation revealed an unidentified body that could not immediately determine sex, age, or race. Forensics was tasked with identifying the victim and cause of death. Based on crime statistics, the most likely profile for the victim was a white male, and the most likely profile for the offender was a black male. However, the joint probability analysis showed it was more likely the victim and offender were the same race and gender. The preliminary forensic report identified the victim as a white female, contradicting the initial predictions.

6. Race of Victim/Offender Race of Offender Race of Victim White Black Other TOTAL White 3017 501 44 3562 Black 226 2864 8 3098 Other 47 26 122 195 Unknown 33 21 2 56 TOTAL 3323 3412 176 6911

7. Sex of Victim/Offender Sex of Offender Sex of Victim Male Female Unknown TOTAL Male 4417 499 71 4987 Female 1754 185 23 1962 Unknown 49 7 19 75 TOTAL 6220 691 113 7024

9. Race of Victim Race of Victim TOTAL White 3562 Black 3098 Other 195 Unknown 56 TOTAL 6911 Race of Victim TOTAL White 51.5% Black 44.8% Other 2.8% Unknown 0.8% TOTAL 100%

10. Sex of Victim Sex of Victim TOTAL Male 4987 Female 1962 Unknown 75 TOTAL 6911 Sex of Victim TOTAL Male 71.0% Female 27.9% Unknown 1.1% TOTAL 100%

12. What is the best prediction as to the race and sex of the offender?

13. Offender Details: Race Race Total White 3,323 Black 3,412 Other 176 Total 6,911 Race Total White 48.1% Black 49.4% Other 2.5% Total 100.0%

14. Offender Details: Sex Race Total Male 6,620 Female 691 Unknown 113 Total 7,024 Race Total Male 88.6% Female 9.8% Unknown 1.6% Total 100.0%

16. How likely is that the victim and the offender are of the same race? Same gender? And does it agree with the preliminary predictions?

17. Joint Profile: Race Offender Total White 48.1% Black 49.4% Other 2.5% Total 100.0% Victim Total White 51.5% Black 44.8% Other 3.6% Total 100.0%

19. Joint Profile: Sex Offender Total Male 88.6% Female 9.8% Unknown 1.6% Total 100.0% Victim Total Male 71.0% Female 27.9% Unknown 1.1% TOTAL 100%

23. Race of Offender Race of Offender Race of Victim White Black Other TOTAL White 3017 501 44 3562 Black 226 2864 8 3098 Other 47 26 122 195 Unknown 33 21 2 56 TOTAL 3323 3412 176 6911

24. Sex of Offender Sex of Offender Sex of Victim Male Female Unknown TOTAL Male 4417 499 71 4987 Female 1754 185 23 1962 Unknown 49 7 19 75 TOTAL 6220 691 113 7024

27. QUESTIONS?