From caller to criminal: How some 911 callers become suspects

ITHACA, N.Y. — When reporting violent events to 911, callers who fail to express expected levels of emotion and urgency may trigger suspicion that they are participants in the crime they are reporting — potentially the first step toward a wrongful conviction, new Cornell University research finds.

In four studies involving roughly 1,800 civilians and 300 law enforcement officers who listened to real or simulated 911 calls, researchers identified five behaviors that might make a caller seem suspicious. Conveying strong emotion and urgency reduced suspicion, while callers perceived to be communicating poorly, guarded in providing information or trying to make a favorable impression drew more suspicion.

Those first impressions can be important, the scholars said, because once someone is a suspect, research has shown that investigators may become prone to confirmation bias – leading them to be more drawn to evidence that confirms, rather than contradicts, a caller’s guilt.

“Having expectations for people’s demeanor on 911 calls is dangerous,” said Jessica Salerno, associate professor of psychology, associate member of the Cornell Law School faculty, and senior author of “From Caller to Suspect: Identifying Behaviors That Trigger Suspicion in 911 Calls,” accepted for publication in Law and Human Behavior. “People communicate in very different ways due to cultural and personality differences, neurodivergence, disabilities, or just the intense stress of the situation. There is no ‘one size fits all’ for responses to traumatic events.”

In the new research, participants listened to real 911 calls reporting violent acts, including shootings, or scripted dialogue based on actual events, performed by male and female professional voice actors. In addition to emotion and urgency, study participants evaluated behavior related to callers’ cognitive load (difficulty communicating), information management (withholding detail) and impression management.

Emotion was cited most frequently — by four out of five study participants — as increasing or decreasing their suspicion. Even when hearing the same 911 call script, violent events reported in a less emotional tone attracted significantly greater suspicion, Salerno said. Results overall were similar across study participants, except that law enforcement officers were more suspicious of male callers; otherwise, no gender bias was detected in laypeople.

Emergency calls may appropriately be scrutinized for factual evidence, the researchers said, but should not be used to infer guilt from how someone sounds – as promoted by some flawed police training.

Better understanding the factors that prompt early suspicion is key to preventing wrongful convictions that are very difficult to overturn, Salerno said.

“The best way to combat a lot of wrongful convictions is to try to prevent the wrong person from being suspected in the first place,” Salerno said, “rather than hoping to fix it later.”

For more, please see this Cornell Chronicle story.