Defense Forensic Exhibit · State of Utah v. Tyler Robinson

Where Was
the Shooter?

Acoustic multilateration places the muzzle source 67.1 meters and 24.5° from the prosecution's claimed position — a discrepancy that is physically impossible to reconcile with the recorded evidence.

Jon Bray · followtheepicenter.com · Preliminary Hearing May 18, 2026 · 11 GPS-verified recorders
⚠
Reasonable Doubt: The prosecution's claimed shot position is acoustically impossible

Five independent lines of acoustic evidence — crack-to-boom timing across 20+ recordings, N-wave TDOA multilateration from 11 GPS-verified recorders, Canon XA55 48kHz crack-to-boom interval, N-wave zero-crossing analysis, and Dr. Rob Maher's independent CNN analysis — all converge on a muzzle source physically incompatible with the prosecution's position by 67.1 meters, 24.5° of bearing, and a 43 ms timing gap that violates the laws of physics.

01 — Position Comparison
Prosecution Claim Disputed

Claimed Shot Position

Coordinate 40°16′41.41″N  111°42′45.90″W
Distance from tent 131.6 m (432 ft)
Bearing from tent 56.4° ENE
Distance from Canon XA55 91.6 m
Crack-boom at Canon XA55 159 ms maximum (hard ceiling)
Source Prosecution assertion
Acoustic Evidence Corroborated

Acoustic Muzzle Source

Coordinate 40°16′43.4″N  111°42′47.0″W
Distance from tent 158.9 m (521 ft)
Bearing from tent 31.9° NNE
Distance from Canon XA55 134.2 m
Crack-boom at Canon XA55 233 ms predicted / 202 ms observed
Source TDOA · 11 recorders · CNN
67.1 meters Spatial separation between
the two positions
24.5° bearing error Angular difference in direction
from tent to each position
43 milliseconds Prosecution crack-boom deficit
at Canon XA55 — physically impossible
02 — Spatial Map
Top-down geometry · Scale 1 px ≈ 0.625 m · Tent origin · North up
50 m 100 m 158 m N BULLET TRAJECTORY 31.9° NNE → tent 54.5 m off-track ⊥ from trajectory TENT 40.27751°N P PROSECUTION CLAIM 131.6 m | 56.4° ENE Canon crack-boom: 159 ms max ✗ 54.5 m off bullet trajectory A ACOUSTIC SOURCE 158.9 m | 31.9° NNE Canon: 202 ms obs / 233 ms pred Lies on bullet trajectory C Canon XA55 GPS-verified nearest pt 24.5° 50 m Bullet trajectory (acoustic) Prosecution bearing 54.5 m ⊥ offset Canon XA55 / nearest pt
03 — Crack-to-Boom Interval at Canon XA55
Crack-to-Muzzle-Blast Interval · Canon XA55 GPS: 40°16′39.24″N 111°42′48.55″W
All values are crack-to-boom intervals measured at the Canon's GPS position — not absolute travel times from shot to tent. Canon is 47.5 m from tent, 134.2 m from acoustic muzzle source, 91.6 m from prosecution position.
Canon XA55 OBSERVED100–300 Hz LF · raw 48 kHz PCM
muzzle blast peak
202 ms
N-wave source PREDICTED134.2 m from Canon · on-axis upper bound
233 ms
Prosecution PREDICTED91.6 m from Canon · absolute maximum
159 ms ✗
Critical Finding — Hard Physical Ceiling

The prosecution's position is only 91.6 meters from the Canon XA55. Using the standard supersonic crack-to-boom formula Δt = d/Vs − d/Vb (Vs = 343 m/s, Vb = 848 m/s), the absolute maximum possible interval from that distance is 159 ms. Off-axis geometry can only decrease this value — never increase it.

The Canon records 202 ms. This is a 43 ms gap that no geometry can close. The acoustic muzzle source at 134.2 m predicts 233 ms on-axis; the 31 ms shortfall from observed is fully explained by the Canon's off-axis position relative to the bullet path — a geometrically consistent result. The prosecution position cannot produce the recorded evidence under any arrangement.

202 ms
Observed at Canon
159 ms
Prosecution Maximum
43 ms
Physically Impossible Gap
Δt = d/Vs − d/Vb  ·  Vs = 343 m/s  ·  Vb = 848 m/s (2,783 fps · mean across 20+ recorders)  ·  Canon position GPS-verified
04 — Five Independent Lines of Evidence
01
Crack-Boom Timing · 20+ Recorders
The supersonic bullet crack followed by the muzzle blast was captured across 20+ independent recordings. The crack-boom gap encodes bullet velocity, distance, and shot geometry. Mean bullet velocity across all recorders: 2,783 fps — consistent with a .30-06 at the acoustic range of ~159 m from tent, not the prosecution's 131.6 m. Vb = 2,783 fps (mean · 20 recorders) → ~159 m ✓
02
TDOA Multilateration · 11 Recorders
Time-difference-of-arrival analysis across 11 GPS-verified recorder positions triangulates the supersonic shock front source. The solution converges on 158.9 m at bearing 31.9° NNE from the tent — not the prosecution's 131.6 m at 56.4° ENE. TDOA solution: 158.9 m | 31.9° NNE · 11-recorder GPS array ✓
03
Canon XA55 Crack-to-Boom · 48 kHz PCM
The Canon XA55 (GPS-verified, 48 kHz uncompressed PCM) is 91.6 m from the prosecution's position and 134.2 m from the acoustic source. Bandpass analysis (100–300 Hz) resolves the muzzle blast at +202 ms after the crack. The prosecution's position has a hard ceiling of 159 ms at this recorder. No geometry closes 43 ms. Observed: 202 ms · Prosecution ceiling: 159 ms · Gap: 43 ms — impossible ✓
04
N-Wave Zero-Crossings · Supersonic Signature
Supersonic bullets produce an N-wave shock front with sub-200 µs zero-crossing intervals. The Canon XA55 confirms 500 sub-200 µs zero-crossings on the built-in channels and 733 on the shotgun — 4–6× more than any phone recording. CH1 saturated at 22,163 clips. Both channels hit the 20.8 µs Nyquist floor. Sub-200 µs ZC confirmed · all 4 channels · Nyquist floor 20.8 µs ✓
05
Dr. Rob Maher · Independent CNN Analysis
Dr. Rob Maher's independent convolutional neural network analysis of the acoustic record corroborates a muzzle source in the ~127–159 m NNE range. Conducted entirely independently of the TDOA and crack-boom calculations, this provides three-way convergence on a location the prosecution's position cannot occupy. Independent CNN corroboration: ~127–159 m NNE ✓
05 — Conclusion

Reasonable Doubt Is Established by the Physical Record

The prosecution places the shooter at 40°16′41.41″N, 111°42′45.90″W — 131.6 meters from the tent at bearing 56.4° ENE, and only 91.6 meters from the Canon XA55 GPS-verified recorder.

Five independent acoustic analyses converge on a muzzle source 158.9 meters away at bearing 31.9° NNE. The Canon XA55 records a crack-to-boom interval of 202 ms. From the prosecution's claimed position, the absolute physical maximum at the Canon is 159 ms — the observed 202 ms exceeds this by 43 ms under any conceivable geometry.

In addition: the prosecution's position is 54.5 meters perpendicular to the acoustic bullet trajectory. A shooter there would have fired on bearing 56.4° ENE. The acoustic record establishes the bullet traveled on bearing 31.9° NNE. These are physically incompatible trajectories.

A 67.1-meter spatial separation, 24.5° angular error, 54.5-meter perpendicular offset from the bullet path, and a 43 ms timing gap that violates physics are far outside any plausible measurement uncertainty for an 11-recorder GPS-anchored 48 kHz array. The acoustic record does not support the prosecution's claimed shooter location. This constitutes reasonable doubt.