missingPersonLR: Likelihood ratio calculation for missing person...

In forrel: Forensic Pedigree Analysis and Relatedness Inference

Likelihood ratio calculation for missing person identification

Description

This is a wrapper function for kinshipLR() for the special case of missing person identification. A person of interest (POI) is matched against a reference dataset containing genotypes of relatives of the missing person.

Usage

missingPersonLR(reference, missing, poi)

Arguments

reference	A ped object with attached markers.
missing	The ID label of the missing member of reference.
poi	A singleton object with genotypes for the person of interest. The marker names of poi must coincide with those of reference. The ID label of poi is irrelevant.

Value

The LRresult object returned by kinshipLR(), but without the trivial H2:H2 comparison.

Examples

#------------------------------------------------
# Example: Identification of a missing grandchild
#------------------------------------------------

set.seed(2509)

### Reference pedigree with missing grandchild (MP)
x = relabel(linearPed(2), old = 5, new = "MP")

# Simulate reference data for grandmother (5 STR markers)
x = setMarkers(x, locusAttributes = NorwegianFrequencies[1:5])
x = profileSim(x, N = 1, ids = 2)[[1]]

### Person of interest 1: Unrelated
poi1 = singleton("poi1")

# Transfer (empty) markers and simulate genotypes
poi1 = transferMarkers(from = x, to = poi1)
poi1 = profileSim(poi1, N = 1)[[1]]

# Compute LR
lr1 = missingPersonLR(x, missing = "MP", poi = poi1)
lr1
lr1$LRperMarker


### Person of interest 2: The true MP

# Simulate MP conditional on reference, and extract as singleton
poi2 = profileSim(x, N = 1, ids = "MP")[[1]]

# Extract MP as singleton
poi2 = subset(poi2, "MP")

# Compute LR
lr2 = missingPersonLR(x, missing = "MP", poi = poi2)
lr2
lr2$LRperMarker

forrel documentation built on March 18, 2022, 5:19 p.m.