Sleep-deprived police officers may struggle to solve crimes and gather critical information, according to a new study conducted by researchers from Iowa State University (ISU).
The study, led by Zlatan Križan, a sleep scientist and psychology professor at ISU, aimed to understand the impact of sleep deprivation on law enforcement officers’ investigative interviews and their ability to establish rapport with interviewees. The findings were published in the journal Scientific Reports.
Križan and his team, including ISU psychology professor Christian Meissner, graduate student Anthony Miller, and retired homicide detective Matthew Jones, recruited 50 law enforcement officers from Arizona, Iowa, Kansas, and Nevada for the study. The participants wore sleep-activity trackers for two weeks and completed daily surveys related to sleep quality, stress levels, hours worked, and self-care habits.
During the study, officers reported their interactions with victims, witnesses, and suspects during actual investigative interviews, highlighting the psychological complexity of such interactions. Establishing a rapport with interviewees is crucial for obtaining valuable information, especially when interviewees are skeptical of law enforcement or resistant to cooperating.
The results of the study revealed that law enforcement officers often experienced insufficient sleep, with less than seven hours per night. They also took a long time to fall asleep, woke up multiple times during the night, and had several days with suboptimal alertness, comparable to mild levels of alcohol intoxication. On days when officers were more fatigued, they reported encountering greater resistance from interviewees and facing more difficulty in establishing rapport. This may be attributed to investigators losing patience during interviews, potentially perceiving interviewees as uncooperative.
According to Meissner, managing one’s emotions and cognitive effort is crucial during effective interviews, but investigators frequently report stress and sleep disruption as part of their job. This study documents the significant influence of sleep and fatigue on the success of investigative interviews and interrogations.
Križan emphasised that fatigue management and ensuring well-rested law enforcement are crucial for enhancing their effectiveness and achieving valid outcomes in investigations. However, finding long-term solutions to sleep deprivation among law enforcement officers, as well as other first responders like firefighters and paramedics, presents challenges. One potential solution could involve adding more staff to alleviate the burden and prevent individuals from feeling overworked. However, this would require increased budgets and a pool of qualified candidates.
While regulations regarding rest requirements exist for certain professions like airline pilots, implementing similar regulations for law enforcement is challenging due to the decentralised nature of police departments. Križan and his team continue their research on how poor sleep affects the ability of police officers to assess the credibility of interview subjects. They are also exploring how individual characteristics may influence an individual’s sensitivity to the adverse effects of fatigue.