CMU researchers develop tool to pinpoint source of gunshots using smartphone videos

A tool developed at Carnegie Mellon University to determine the location of gunshots correctly pinpointed where the shots came from in the 2017 mass shooting on the Las Vegas Strip, CMU researchers said.

Researchers tested the value of the tool by analyzing three videos that recorded gunshots in the first minute of the Las Vegas massacre.

The Video Event Reconstruction and Analysis (VERA) system correctly determined the shooter was in the north wing of the Mandalay Bay hotel.

The Oct. 1, 2017, shooting was the deadliest in U.S. history, killing 58 and wounding hundreds of others in a barrage of more than 700 gunshots.

The VERA system uses audio in videos to detect gunshots and analyzes it to determine the location of the shots and the type of gun being used, according to CMU researchers Jay D. Aronson and Alexander Hauptmann.

To do so accurately, three videos of an incident are needed to triangulate the location of the shots, Aronson said.

“If you know where a camera is and you have the sounds of the bullet leaving the muzzle and then you can find the sound when the bullet breaks the sound barrier, you can use those two moments of sound to determine where the shots were fired,” Aronson said. “Basically, you just use geometry and sound to put it all together.”

It can be used by both law enforcement and human rights groups.

Aronson is a history professor at CMU and director of the university’s Center for Human Rights Science. He is interested in the technology because of potential to help human rights organizations investigate protests and other violent incidents to help prove who is responsible for the violence.

One of the seeds of inspiration that led to development of VERA was the 2014 massacre in Kiev’s Maidan Square in Ukraine, where at least 50 anti-government protesters were killed.

“The question was: Who did it, and were they justified?” Aronson said.

Aronson and Hauptmann, a research professor in CMU’s Language Technologies Institute, helped investigators in Ukraine case using video from the protest.

VERA builds on that work and provides an automated system where a computer analyzes video from an incident and calculates where the gunshots were fired.

VERA can’t sift through videos being made moments after something happens, but it can be used by investigators to piece together what happened after the fact.

Aronson and Hauptmann presented VERA and released it for public use at an international computer conference earlier this year.

People can upload videos of an incident where gunshots were recorded, and VERA synchronizes the videos, marks when the gunshots happened and then calculates where they were likely fired from.

They’re still working to perfect the tool and determine its uses, Hauptmann said.