VERIFIED FORENSIC ACOUSTICS

FA-2026-001: Muzzle Blast Source Localization

TDOA Multilateration Analysis — Charlie Kirk Shooting, Utah Valley University

September 10, 2025 | Analysis completed February 2026

EXECUTIVE SUMMARY

Forensic acoustic analysis of four cell phone recordings captured during the shooting of Charlie Kirk at UVU's Fountain Courtyard. Using Time Difference of Arrival (TDOA) multilateration on muzzle blast onset times, the analysis localizes the shot origin to approximately 2.3–3.0 meters south of the stage center, with a 95% confidence ellipse of 2.42 × 1.01 meters.

▸ Muzzle blast source located ~2.6m south of stage center (95% confidence ellipse: 2.42 × 1.01m)

▸ Supersonic crack confirmed at all 4 receivers (crack precedes blast by 10–24ms)

▸ Synchronization accuracy: ±0.021ms (±21μs) — negligible position error contribution

▸ Solution stable under jackknife leave-one-out (max shift 2.4m when R4 dropped)

▸ PA correction uncertainty bounded to <0.7 meter across 5 independent models

Synced Recordings

349.7

m/s Speed of Sound

±21μs

Sync Accuracy

~2.6m

From Stage Center

10K

Monte Carlo Runs

Local coordinate system: receivers (green), speakers (blue), TDOA solution (diamond), 95% confidence ellipse (dashed).

ANALYSIS SECTIONS

Methodology

10-phase forensic pipeline from evidence intake through TDOA multilateration to uncertainty quantification.

Evidence

4 cell phone recordings, environmental parameters, receiver positions, and chain of custody documentation.

Analysis

Synchronization, spectral decomposition, onset picking, and PA correction walkthrough.

Results

TDOA solution with interactive visualizations, confidence bounds, and stability analysis.

Technical Appendix

Complete equations, parameters, data tables, and Monte Carlo methodology reference.

This analysis presents only the physical acoustics. It locates where a sound originated. It does not address who, why, or any other investigative questions beyond the acoustic evidence.