CASE STUDY The Case of the Body in the Bag The late spring morning broke along the banks of a river. Robert

CASE STUDY

The Case of the Body in the Bag

The late spring morning broke along the banks of a river. Robert Donkin, an elderly retiree with fishing pole in hand, slipped through the underbrush that lined the river's banks. As he neared the shore, he saw a rather large canvas bag floating in the water, held by foliage that leaned over the river. The bag appeared to be stuffed, well-worn, and heavily stained. Upon closer inspection, Mr. Donkin observed what he believed to be hair floating through the bag's opening. Marking the spot of his discovery, the fisherman fetched the authorities.

Preliminary investigation at the scene revealed a body in the bag. Unfortunately, it was impossible to identify the corpse's sex or race immediately. Estimating age was also out of the question. Forensics was assigned the task of identifying the victim and estimating the cause and time of death. While waiting for the forensics analysis, you, as the detective in charge, have gathered the information shown concerning victim-offender relationships from recent reports from the FBI.

Using the information contained in the tables, you are to develop a preliminary profile of the victim and offender by answering the following questions:

How likely is it that the offender is at least 18 ?
How likely is it that the offender is white?
How likely is it that the offender is male?
Assuming that ethnicity and gender are independent, how likely is it that the offender is a white male?
How likely is it that the offender is either white or male?
How likely is it that the victim and the offender are from the same age category?
How likely is it that the victim and the offender are from different age categories?
How likely is it that the victim and the offender are of the same race?
How likely is it that the victim and the offender are of different races?
How likely is it that the victim and the offender are of the same sex?
How likely is it that the victim and the offender are of different sexes?
Without knowing the contents of the forensic team's report, what is your best prediction of the age, race, and sex of the victim? Explain your reasoning.
What is your best prediction as to the age, race, and sex of the offender? Explain your reasoning.
Soon after you finished this analysis, the preliminary forensics report was delivered to your desk. Although no identification had been made, the autopsy suggested that the cause of death was blunt-force trauma and that the body had been in the water at least two weeks. By using a variety of techniques, it was also determined that the victim was a white female with blonde hair. She was estimated as being in her mid-thirties, showed no signs of having had children, and was wearing no jewelry.
Based on this new information, you develop a new offender profile by answering the following questions:
How likely is it that the offender is at least 18 ?
How likely is it that the offender is white?
How likely is it that the offender is male?
How likely is it that the victim and the offender are from the same age category?
How likely is it that the victim and the offender are from different age categories?
How likely is it that the victim and the offender are of the same race?
How likely is it that the victim and the offender are of different races?
How likely is it that the victim and the offender are of the same sex?
How likely is it that the victim and the offender are of different sexes?
What is your best prediction of the age, race, and sex of the offender? Explain your reasoning.
Did your answers to the offender questions change once you knew the age, race, and sex of the victim? Explain.

Suppose that $45 \%$ of murder victims were known to be related to or acquainted with the offender, that $15 \%$ were murdered by an unrelated stranger, and that for $40 \%$ of victims relationship to their killer is unknown. Based on all the information available, complete your offender profile for this case.