By Lindsey McLeod

In recent years, Silicon Valley has taken on a range of issues that span the spectrum from consumer entertainment to government security and data protection.[1] Recently, Silicon Valley executives have made the jump into the gun violence arena, attempting to use technology to assist police officers in responding to shots fired. The technology, one of a many apps that are currently emerging in the tech-security world, is called ShotSpotter.[2]

ShotSpotter was initially developed to combat the growing gun violence program in urban areas within the United States.[3] The developers intended the app to meet the growing need to combat gun violence in the communities most affected.[4] The developers recognized a problem in that those who are most significantly impacted by gun violence on a regular basis are the least likely to report it, resulting in incident reports that grossly misrepresent the problem at hand.[5] For example, fewer than one in five shooting incidents are reported to police, and when reports are made to the police, the account is rarely accurate.[6] This miscommunication and misrepresentation causes police to respond inappropriately, further perpetuating the gun violence problem.[7]

ShotSpotter is cloud-based technology that creates a system similar to a large cyber network implanted over a geographic area, equipping that area with microphones and software monitoring.[8] The microphones are designed to suppress ambient noise and pay particular attention to loud “trigger” noises, which respond to “booms” and “bangs,” referred to as “impulsive noises.”[9] When a sound is triggered, the system sends an alert to the ShotSpotter headquarters location, where the monitoring review service—comprised of trained acoustic experts—makes the final determination regarding the origin of the audio.[10] When these impulsive noises are deemed the result of gunfire, the local police are alerted to the disturbance and dispatched to the area.[11] The police can then interrupt the event and terminate the gun violence event.

Despite the obvious need for police intervention like that which this app creates, critics of the app point to the lack of arrests it produces as evidence of the app’s ineffectiveness. For example, in Brockton, MA, between January 1, 2013 and September 28, 2015, the ShotSpotter technology alerted police of gun activity 296 times, yet those alerts led to only two arrests.[12] These unimpressive statistics represent the nationwide trend of the impact that ShotSpotter has had on combatting gun violence, increasing the frequency of alerts but doing little in terms of arrests.[13]

The developers, however, argue that this data is not representative of a technological failure; instead, the developers argue that this technology was not developed to lead to arrests, but rather to combat the problem at its origin.[14] Ralph Clark, the CEO of ShotSpotter, argues that “only a small number of individuals are responsible for most of a city’s gunfire and any tools available to get those folks off the street are important”.[15] Thus, though ShotSpotter has not led to an increase in arrests, the understanding by the residents of these high-risk communities is that police will respond quickly to the alert of gunfire, which will likely to lead to a decrease in the gunfire, and consequently a decrease in violence.[16] Effectively, the presence of such technology within high-risk communities should abolish the need for this technology altogether.[17]

Beyond the prosecution numbers of gun violence perpetrators, there is a legal issue presented in terms of the admissibility of material created by this technology. Although the infrequency of arrests suggests that there is little need for the use of this evidence at trial, the mere potential for its use nevertheless poses an interesting legal question. The use of this technology creates a feeling of a “big brother” presence, a phenomenon that tends to invoke Fourth Amendment concerns.[18] Additionally, this technology appears to invoke privacy concerns that, although not explicitly protected by the Constitution, are inferred by the Supreme Court rulings in cases such as Roe v. Wade and Bowers v. Hardwick.[19] Despite these concerns, United States v. Katz states that privacy concerns invoking the Fourth Amendment’s protection from unreasonable searched and seizures apply only to the search of a person, not the place. In these instances, then, the party supporting the ShotSpotter evidence could argue that this material is collected from the place, not the parties, that are present at the scene of the crime and is thus admissible.[20]

The courts consider the evidentiary issues loosely, which here would result in support of combatting crime as opposed to protecting the accused. A Massachusetts Superior Court recently deemed the material admissible in the first-degree murder trial of Dwayne Moore and Edward Washington.[21] In this trial, an expert witness from SST Inc. a, the company that manufactures ShotSpotter, testified about the timeframe during which the shots were fired and the time lapse between shots.[22] The use of this evidence in the Massachusetts Superior Court suggests that this evidence will be seen more frequently in the coming years in criminal proceedings as a means to prove, or disprove, the location and details of a shooting.[23] Because of the growing presence of these technologies in the criminal justice community, criminal defense attorneys should anticipate the impact that these technologies could have on evidence admitted at trial going forward.





[1] See Megan Smith, Expanding the Pentagon’s Silicon Valley Office, (May 20, 2016) (Secretary of Defense Ash Carter is taking bold steps to help the U.S. military take advantage of commercially driven technology and innovation).

[2] See ShotSpotter, (Nov. 21, 2016)

[3] See id.

[4] See id.

[5] See Law Enforcement Resources, (Nov 17, 2016)

[6] See id.

[7] Id.

[8] Here’s How the NYPD is Expanding ShotSpotter,, (Nov. 17, 2016)

[9] See id.

[10] See id.

[11] See id.

[12] See Matt Drange, ShotSpotter Alerts Police to Lots of Gunfire, But Produces Few Tangible Results, FORBES (Nov.

[13] See id.

[14] See John Biggs, ShotSpotter CEO Ralph Clark Talks About the Future of City Surveillance, Tech Crunch (Nov. 20, 2016)

[15] See id.

[16] See id.

[17] See id.

[18] U.S. Const. amend IV.

[19] See The Right of Privacy, Exploring Constitutional Conflicts, UMKC Law (Nov. 21, 2016)

[20] See United States v. Katz, 389 U.S. 347 (1967).

[21] See Stephen Neyman, Massachusetts Criminal Trial Using Gunshot Detection System to Support Witness Testimony in High Profile Murder Trial, Massachusetts Criminal Defense Attorney Blog (Feb. 2012)

[22] See id.

[23] See id.


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