Montana State University

MSU professor an expert resource for investigative, forensic communities

March 6, 2013 -- By Sepp Jannotta, MSU News Service

MSU professor Rob Maher, who is a nationally recognized expert on audio forensics, first published research on gunshot acoustics in 2006. Since then he and his MSU colleague Steven Shaw, MSU professor of electrical and computer engineering, have explored further the problem of using recordings to provide directional information about gunfire.    High-Res Available

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Tel: (406) 994-4571

BOZEMAN - In recent years, an increasing number of criminal trial lawyers and investigators have been dialing up Montana State University professor Rob Maher.

"I probably get calls from attorneys two or three times a month," said Maher, professor and head of MSU's Electrical and Computer Engineering Department.

Maher, who specializes in audio forensics, has seen his research on gunshot acoustics spread through the media community that serves private investigators and, in particular, the forensics specialists.

When the national PI press needs an expert on how to analyze the audio signals from a gunshot or how background sounds can - or can't - be better understood, Maher is often a go-to resource.

In January, Maher led the lineup on the American Private Investigator podcast with Paul Jaeb. During a nearly 20 minute interview (click here to listen), Maher offered his thoughts about the role of mobile device recordings as forensic evidence, among other topics.

"People in the industry pay attention to that program because Paul really covers a wide range of topics and looks to the science behind forensics," Maher said.

That is important for Maher, who believes peer-reviewed science has set the record straight for a public infatuated with forensics/investigator television shows like "CSI: Crime Scene Investigation."

Maher said the research he's been doing on audio forensics hopefully helps delineate the line between science and pseudoscience when it comes to what kinds of things should be thought of as evidence in a criminal trial.

"It's the 'CSI' effect," Maher said. "Jurors think every case gets this magical level of scrutiny and technology applied to it and many times attorneys are having to explain to juries that the things they see on television may not be possible."

Science has led to some amazing technology, however, with several companies selling proprietary commercial products for use by law enforcement and the military. Maher pointed to gunshot-detection microphone products like BBN's Boomerang system for military sniper detection, and ShotSpotter, which can help authorities triangulate and locate the source of gunfire.

Maher said some patent claims from commercial products have referenced his paper on "Modeling and signal processing of acoustic gunshot recordings," published in 2006.

Maher said subsequent research conducted in collaboration with his MSU colleague Steven Shaw, MSU professor of electrical and computer engineering, has explored further the problem of using recordings to provide directional information about gunfire.

Maher and other researchers have found that, in addition to the unique acoustic geometry of the environment where a shot is fired - and how sounds will reverberate off surfaces - the waveform signal has much to do with the relationship of the microphone to the angle of the gun barrel.

There are many misconceptions about audio forensics and gunshot recordings. Maher said the most common is that investigators can connect a waveform signal to a specific firearm. 

In addition, investigators reviewing recordings from mobile devices face a conundrum because inferior microphones typically produce recordings of limited forensic value, Maher said. Maher raised that issue in a recent interview for a story in Forensic Magazine (see the story here).

Given the number of mobile devices in any given public setting and because recordings of this kind will get analyzed more and more often, Maher said he will continue to publish research on the issue.

And his phone will likely keep ringing.

Contact: Rob Maher, (406) 994-2505 or