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 position on the Losee rooftop consistent with published FBI evidence-marker photographs — a discrepancy the recorded audio can neither predict nor accommodate under standard supersonic-shot geometry.

Jon Bray · followtheepicenter.com · Preliminary Hearing May 18, 2026 · 11 GPS-verified recorders
⚠
The recorded acoustics do not place the shot at the FBI-marked rooftop position

Four internally consistent acoustic lines — crack-to-boom timing across 20+ recordings, N-wave TDOA multilateration from 11 GPS-verified recorders, the Canon XA55 48 kHz PCM crack-to-boom interval, and N-wave zero-crossing analysis — converge on a muzzle source approximately 158.9 m at bearing 31.9° NNE from the tent. This is 67.1 m and 24.5° removed from the location on the Losee rooftop identified by published FBI evidence-marker photographs, and produces a 43 ms gap between the observed Canon XA55 crack-boom interval (202 ms) and the geometric ceiling from the evidence-marker location (159 ms). Dr. Rob Maher's independent CNN analysis places the shot at approximately 150 m in the Losee direction, broadly consistent with a supersonic rifle round in this general area. His finding corroborates the shot's direction and range class but does not on its own distinguish between the FBI evidence-marker position and this analysis's acoustic muzzle source, both of which fall within his range.

01 — Position Comparison
FBI Evidence-Marker Location Photograph-Derived

Losee Rooftop Position

Coordinate (approximate) 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 geometric maximum
Source Inferred from FBI evidence-marker photos
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 Observed Canon XA55 interval
exceeds evidence-marker geometric ceiling
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) Evidence-marker 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 the FBI evidence-marker 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
Evidence-marker predicted91.6 m from Canon · geometric maximum
159 ms ✗
Critical Finding — Hard Physical Ceiling

The FBI evidence-marker 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 geometric maximum 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 from the evidence-marker position. 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. A firing position located exactly at the FBI evidence markers cannot produce the recorded interval. The actual firing position may have been offset from the evidence markers by several meters (ejected .30-06 brass typically lands 4–8 ft from the shooter), but even generous offsets do not close a 43 ms gap: to reach 202 ms at the Canon requires a distance of approximately 134 m from that recorder, which places the shot well outside any plausible offset from the evidence markers on the Losee rooftop.

202 ms
Observed at Canon
159 ms
Evidence-Marker 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 131.6 m implied by the FBI evidence-marker position. 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 131.6 m at 56.4° ENE implied by the FBI evidence-marker position. 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 FBI evidence-marker 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 evidence-marker position has a geometric ceiling of 159 ms at this recorder. No geometry closes the 43 ms gap. Observed: 202 ms · Evidence-marker ceiling: 159 ms · Gap: 43 ms ✓
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 CNN analysis of the acoustic record places the shot at approximately 150 m in the Losee direction, corroborating a supersonic rifle-class projectile fired from the general NNE Losee area. His finding is broadly compatible with both the FBI evidence-marker position (~127 m) and this analysis's acoustic muzzle source (~159 m), which both lie in the same direction from the tent. Maher's contribution establishes independent third-party agreement on the general area and character of the shot; it does not, on its own, adjudicate between the evidence-marker position and the acoustic muzzle source. The 43 ms Canon XA55 gap is this analysis's own contribution. Independent CNN corroboration: ~150 m Losee direction · supersonic rifle-class ✓
05 — Conclusion

The Recorded Acoustics Do Not Place the Shot at the FBI Evidence-Marker Position

The FBI evidence markers on the Losee rooftop, as visible in published photographs, are consistent with a firing position at approximately 131.6 meters from the tent at bearing 56.4° ENE, and approximately 91.6 meters from the Canon XA55 GPS-verified recorder. The FBI and prosecution have not published the precise firing coordinates; this analysis works from the location inferred from the evidence-marker photographs.

Four internally consistent acoustic analyses converge on a muzzle source approximately 158.9 meters away at bearing 31.9° NNE. The Canon XA55 records a crack-to-boom interval of 202 ms. From the FBI evidence-marker position, the geometric maximum at the Canon is 159 ms — the observed 202 ms exceeds this by 43 ms under any geometry consistent with a shot originating at that position.

The FBI evidence-marker position is 54.5 meters perpendicular to the acoustic bullet trajectory established by this analysis. A shot from that position would have traveled on bearing 56.4° ENE from the tent. The acoustic record indicates the bullet traveled on bearing 31.9° NNE. Even allowing for reasonable offset between where FBI investigators marked evidence and where a shooter actually stood (ejected .30-06 brass typically lands 4–8 ft from the shooter), the discrepancy is too large to close: reaching 202 ms at the Canon requires approximately 134 m from that recorder, well beyond any plausible offset from the marked evidence area.

Dr. Rob Maher's independent CNN analysis places the shot at approximately 150 m in the Losee direction, consistent with a supersonic rifle-class shot from the general NNE area of the Losee building. His finding corroborates the direction and range class of the shot but does not on its own distinguish between the FBI evidence-marker area and this analysis's acoustic muzzle source, both of which lie in the same general direction from the tent.

A 67.1-meter separation between the two positions, a 24.5° angular difference in bearing, a 54.5-meter perpendicular offset from the acoustic bullet path, and a 43 ms gap between the observed Canon XA55 interval and the geometric ceiling from the evidence-marker position, together, are far outside the measurement uncertainty of an 11-recorder GPS-anchored 48 kHz array. The acoustic record supports a firing position different from the one implied by the FBI evidence-marker photographs. This analysis submits that discrepancy for examination.