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Geospatial Analysis

Mapping Safety: LAPD Crime Density & Arrest Efficiency

By normalizing 2020–Present LAPD incident data against land area and population demographics, this analysis challenges the traditional "hotspot" narrative, revealing where density strains resources and how victim demographics shift across crime types.

Executive Summary

Volume vs. Density

Raw case counts suggest large precincts like 77th Street are the most dangerous. However, normalizing for land area reveals Central Precinct as the true density hotspot. The analysis also uncovers a disconnect between crime volume and arrest efficiency in these high-density zones.

Design Approach

LOD Expressions for Independence Testing: We used Level of Detail (LOD) reference lines to calculate "expected" victimization rates if crime type and descent were independent. Deviations from these lines highlight where specific demographic groups are disproportionately targeted.

Key Insights

  • Property Crime Dominance: Accounts for ~65% of all incidents, driven by theft-from-vehicle.
  • Violent Crime Demographics: Hispanic victims make up ~51% of violent crimes. While this seems high nationally, it tracks closely with LA's population (~48% Hispanic), indicating the trend is largely proportional to local demographics.
  • Age & Homeownership: Property crime victims skew White as age increases, correlating with higher homeownership rates in older demographics.

The Dataset

NIBRS-compliant LAPD records (2020-present). Data was aggregated to the 21-precinct level and normalized by square mileage to correct for the "large jurisdiction bias" that often skews heatmaps.

Visual Strategy

Sunburst Charts break down the LAPD/UCR hierarchy (Crime Type > Subtype). Dual-Axis Maps contrast absolute volume vs. relative density. Stacked Bars reveal age-based demographic shifts that aggregate metrics hide.

Inference

Descent % of victims largely mirrors LA's population (~48% Hispanic), but deviations exist. Property theft appears tied to neighborhood wealth rather than victim profile, whereas violent crime clustering indicates systemic vulnerabilities in specific communities.