8127/frame/fm

 
Appendix E
 
Sample Likelihood and RMNE Calculations
3.
 
Assuming neither race, number, nor identity of donors
1.
 
Assuming the presence 
of the boyfriend
The probability of the profile is this many 
times more likely if the boyfriend and sus-
pect are the donors than if the boyfriend
and a random man of the indicated race
are the donors
2.
 
Assuming neither donor 
is identified
The probability of the profile is this many
times more likely if the suspect and a ran-
dom man are the donors than if two ran-
dom men of the indicated race are the
donors
P E
P E
Boyfriend
Suspect
Boyfriend
random man
AfAm
E-
Cauc
6.6E-10
1, 500, 000, 000
Hisp
7.7E-11
13, 000, 000, 000
+
(
)
+
(
)
=
=
1
5 7
10
1 700 000 000
.
,
,
,
P E
P E
Suspect
random man
random men
AfAm
E
E-
Cauc
E-
E-
4 , 000, 000
Hisp
E-
E-
200, 000, 000
+
(
)
(
)
=
−
=
=
=
2
4 0
09
1 2
16
33 000 000
4 1
08
9 1 16
5
2 7
07
1 3
15
.
.
,
,
.
.
.
.
RMNE
Freq = 5.4E-07
= 1 in 1 800 000
,
,
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355
 
Appendix F
 
Fundamental Principles and Concepts 
of Criminalistics
The Crime
 
Thinking Is Allowed
 
The Origin of Evidence
 
The Principles of Criminalistics
•
 
Divisible matter
Matter divides into smaller component parts when sufficient force
is applied. The component parts will acquire characteristics created
by the process of division itself and retain physicochemical prop-
erties of the larger piece.
 
Three corollaries:
 
Corollary 1
: Some characteristics retained by the smaller pieces are
unique to the original item or to the division process. These traits
are useful for individualizing all pieces to the original item.
 
Corollary 2
: Some characteristics retained by the smaller pieces are
common to the original item as well as to other items of similar
manufacture. We rely on these traits to classify the item.
 
Corollary 3: 
Some characteristics of the original item will be lost or
changed during or after the moment of division and subsequent
dispersal; this confounds the attempt to infer a common source.
•
 
Transfer
(
 
Locard exchange principle
)
Conventionally: every contact leaves a trace.
As defined here: when two objects come in contact, material may
be exchanged.
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356
Principles and Practice of Criminalistics
 
The Crime
 
The Practice of Criminalistics