Article

Shadow Forensics: Uncovering 911 Call Analysis

Christopher Lau

Clinical Associate Professor, Co-Director, Wisconsin Innocence Project, University of Wisconsin Law School. 2026 Scholarly Papers Competition Finalist.

For feedback and engagement, thank you to Valena Beety, Teneille Brown, Edward Cheng, Catherine Crump, Eve Hanan, Daniel Harawa, Randy Hertz, Alexis Hoag-Fordjour, Nathan Rouse, Maneka Sinha, Sonja Starr, and Lisa Washington. Thank you as well to workshop organizers and participants of CrimFest, Decarceration Law Professors Workshop, N.Y.U. Clinical Law Review Writers’ Workshop, Chicagoland Junior Scholars Conference, and Vanderbilt University’s Evidence Summer Workshop. For excellent research assistance, thank you to Ismail El-Hassan, Demetri Sweat, and Grace Woo.

30 Jul 2026

Junk forensics have played a central role in wrongful convictions. From bitemark evidence to hair microscopy, from arson investigation to toolmark comparison, courts have repeatedly allowed testimony about techniques and methodologies that have no basis in reliable science. The result has been hundreds of exonerations, and likely thousands more wrongful convictions. One of the newest forensic techniques is 911 Call Analysis. Proponents claim the technique can identify, via 911 callers’ words and phrasing—including how someone requests help—whether they are the perpetrator of a crime. Despite study after study debunking the reliability of the technique, police departments and prosecutor offices continue to pay for call analysis trainings, and prosecutors continue to use 911 call analysis to seek convictions.

While admission of the technique into criminal cases has followed the same arc of junk forensics before it, 911 call analysis is particularly pernicious because it operates in the shadows. The underlying methods are never disclosed and the founders of the technique are never proffered as experts. Instead, 911 call operators or police officers testify about the culpability of 911 callers after attending a call analysis training. The effect is that the technique largely escapes Daubert or Frye evidentiary challenge. This Article introduces the concept of “shadow forensics” to understand this problem both in the 911 and broader forensic context. This Article makes three primary contributions. One, it offers the concept of shadow forensics: a set of practices that police and prosecutors use to shield forensic techniques, like call analysis, from evidentiary oversight. Second, it provides the first legal discussion of 911 Call Analysis and situates it within the broader problem of junk forensics in the criminal legal system by reviewing the empirical studies that have repeatedly debunked the technique. It then builds on the literature that examines the failure of courts to exclude unreliable forensics from the criminal system. Finally, it discusses proposals to stop the spread of the technique, and of other Shadow Forensics that escape evidentiary scrutiny.

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