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THE BODY IN THE BAG Presenters: Dina Gaughan, Megan Poole, & Amy Shuleski February 24, 2010 MBA 512

Probability Presentation

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Page 1: Probability Presentation

THE BODY IN THE

BAGPresenters:

Dina Gaughan, Megan Poole, & Amy Shuleski

February 24, 2010

MBA 512

Page 2: Probability Presentation

Man Finds large canvas bag floating in river

Preliminary investigation reveals body

Sex/Race/Age Unknown

Body in the Bag

Page 3: Probability Presentation

Victim and Offender – Adults over 18yrs of age

Victim/Offender Relationships◦ 2003 Uniform Crime Reports – FBI

http://www.fbi.gov/ucr/03cius.htm Analysis Profiles

◦ Victim◦ Offender◦ Joint

Waiting on Forensics Analysis

Identify Preliminary Profile

Page 4: Probability Presentation

Race of OffenderRace of Victim

White Black Other TOTAL

White 3,017 501 44 3,562

Black 226 2,864 8 3,098

Other 47 26 122 195

Unknown 33 21 2 56

TOTAL 3,323 3,412 176 6,911

Page 5: Probability Presentation

Sex of OffenderSex of Victim

Male Female Unknown

TOTAL

Male 4,417 499 71 4,987

Female 1,754 185 23 1,962

Unknown 49 7 19 75

TOTAL 6,220 691 113 7,024

Page 6: Probability Presentation

Classical Method◦ P (E) = Number of ways that E can occur

Number of possible outcomes

Addition Rule◦ P (A or B) = P (A) + P (B)

Multiplication Rule◦ P (A&B) = P (A) * P (B)

Probability Formulas

Page 7: Probability Presentation

(Classical Method)Race:

◦White: 3,562 / 6,911 51.5%◦ Black: 3,098 / 6,911 44.8%◦ Other: 195 / 6,911 2.8%◦ Unknown: 56 / 6,911 .8%

Sex:◦Male: 4,987 / 7,024 71%◦ Female: 1,962 / 7,024 27.9%◦ Unknown: 75 / 7,024 1.1%

Victim Profile Prediction

Page 8: Probability Presentation

(Addition Rule)

White or Black◦=(3562/6911) + (3098/6911) = 96.4%

Male or Female◦=(4987/7024) + (1962/7024) = 98.9%

Victim Profile Prediction

Page 9: Probability Presentation

(Multiplication Rule) White & Male

=(3562/6911) * (4987/7024) = 36.6% White & Female

=(3098/6911) * (1962/7024) = 14.4% Black & Male

=(3098/6911) * (4987/7024) = 31.8% Black & Female

=(3098/6911) * (1962/7024) = 12.5%

Victim Profile Prediction

Page 10: Probability Presentation

Victim Profile Prediction

38%

15%

33%

13%

Victim Sex and Race Profile

White & MaleWhite & FemaleBlack & MaleBlack & Female

Page 11: Probability Presentation

(Classical Method)Race:

◦ White: 3,323 / 6,911 48.1%◦Black: 3,412 / 6,911 49.4%◦ Other: 176 / 6,911 2.5%◦ Unknown: 56 / 6,911 0.8%

Sex:◦Male: 6,220 / 7,024 88.6%◦ Female: 691 / 7,024 9.8%◦ Unknown: 113 / 7,024 1.6%

Offender Profile Prediction

Page 12: Probability Presentation

(Addition Rule)

White or Black◦=(3323/6911) + (3412/6911) = 97.5%

Male or Female◦=(6220/7024) + (691/7024) = 98.4%

Offender Profile Prediction

Page 13: Probability Presentation

(Multiplication Rule) White & Male

◦ = (3323/6911) * (6220/7024) = 42.6% White & Female

◦ =(3323/6911) * (691/7024) = 4.7 % Black & Male

◦ =(3412/6911) * ( 6220/7024) = 43.7% Black & Female

◦ =(3412/6911) * (691/7024) = 4.9%

Offender Profile Prediction

Page 14: Probability Presentation

Offender Profile Prediction

44%

5%

46%

5%

Offender Sex and Race Profile

White & MaleWhite & FemaleBlack & MaleBlack & Female

Page 15: Probability Presentation

(Multiplication Rule) Likelihood of Victim & Offender same

race:◦White: .515 x .481 24.8%◦Black: .448 x .494 22.1%◦Other: .028 x .025 .1%

Likelihood of Victim & Offender same sex:◦Male: .71 x .88 62.9%◦Female: .279 x .098 2.7%◦Unknown: .011 x .016 .02%

Joint Profile Prediction

Page 16: Probability Presentation

Victim White & Male - 36.6%

Offender Black & Male - 43.7%

Joint – Both are White: 24.8% (Disagrees with above

Prediction) Male: 62.9% (Agrees with above

prediction)

Profile Predictions

Page 17: Probability Presentation

No Identification Autopsy

◦ In water for 2 weeks Forensics Information Recovered

◦ White Female◦ Blonde Hair◦ Mid 30’s◦ No children◦ No jewelry

Forensics Analysis - Victim

Page 18: Probability Presentation

Victim Profile Probability did not match the Forensic Analysis

Analysis DeterminedWhite Female

ProbabilitiesWhite Male – 36.6 %

White & Female - 14.4%

Forensics Analysis - Victim

Page 19: Probability Presentation

Based on Victim’s Race – Likelihood Offender is:

White◦ 3,017/3,562 = 84.7 %

Black◦ 501/3,562 = 14.1 %

Other◦ 44/3,562 = 1.7 %

Offender Profile Posting

84%

14%

2%

WhiteBlackOther

Page 20: Probability Presentation

Based on Victim’s Sex– Likelihood Offender is: Male

◦ 1754/1962 = 89.4 % Female

◦ 185/1962 = 9.4 % Unknown

◦ 231/1962 = 1.2 %

Offender Profile Posting

84%

14%

2%

WhiteBlackOther

Page 21: Probability Presentation

(Multiplication Rule) White and Male

◦ .847 * .894 = 75.7 %

Probability that the Offender isWhite and Male is 75.7 %

Official Offender Profile Posting

Page 22: Probability Presentation

Have you seen this man?If so, dial 911

White Male

Questions?