Like many first responders, law-enforcement investigators and detectives often struggle with sleep. Late-night shifts, stress, and the 24-hour nature of crime can throw off biological clocks and cut sleep cycles short. Together with the negative health implications, recent research indicates officers who’re fatigued have a harder time collecting information that would bring justice to victims.

Zlatan Križan, a sleep scientist and psychology professor at Iowa State University, led the study. He says previous research, including his own, shows that folks who’ve lost sleep have trouble controlling their emotions and keeping themselves on task.

Unfortunately, there hasn’t been a whole lot of research in regards to the role of sleep for individuals who conduct high-stakes investigations. We desired to see what real detectives and law enforcement officers experience during their investigative interviews because we all know that they are often getting less sleep than the really useful amount and often experience sleep disorders.”

Zlatan Križan, sleep scientist and psychology professor at Iowa State University

With ISU psychology professor Christian Meissner, graduate student Anthony Miller and retired homicide detective Matthew Jones, Križan conducted a study with 50 law-enforcement officers from Arizona, Iowa, Kansas and Nevada. Participants wore a sleep-activity tracker for 2 weeks and accomplished a day by day survey, which included questions related to sleep quality, stress, hours worked and self-care (e.g., hobbies, exercise.)

Officers also reported their interactions with victims, witnesses, or suspects during actual investigative interviews in the sector, which Križan emphasizes are psychologically complex. As a way to get useful information that would solve a case, he says investigators need to ascertain a rapport or relationship with the opposite person. That will be hard to do during a brief interaction, especially if the interviewee is skeptical of law enforcement, attempting to cover up a criminal offense, or just annoyed with having their day interrupted. Investigators might have to alter tactics or strategies.

“Conducting an efficient interview requires considerable cognitive effort and the flexibility to administer one’s emotions. Investigators often informally report considerable stress and sleep disruption as an element of the job. For the primary time, the present study documents how an investigator’s sleep and fatigue can significantly influence the success of an interview or interrogation,” says Meissner.

Key findings

After analyzing data from the sleep-activity trackers and using biomathematical modeling to estimate day by day fatigue, the researchers found officers often:

• Slept lower than seven hours per night,
• Took longer than average to go to sleep,
• Woke up multiple times in the course of the night, and
• Experienced several days with suboptimal levels of alertness, a few of which were on par with mild levels of alcohol intoxication.

Additionally they found strong evidence linking sleep with several core elements of investigator interviews. One of the striking findings was that officers reported greater resistance from interviewees and more difficulty establishing rapport on days once they were more fatigued. Križan says one possible explanation is that drained investigators are more apt to lose their patience and perceive interviewees as uncooperative.

One other vital finding from the study backed this up. Sleep-deprived participants reported difficulties specializing in their work and managing their emotions. These results were probably amongst officers with late-night and early-morning shifts.

“The study results indicated that less fatigued officers and investigators could also be higher equipped for reaching investigative solutions and bringing appropriate culprits to justice,” says Križan. “Fatigue management and wanting well-rested law enforcement is de facto vital for ensuring each their effectiveness and ensuring valid outcomes of investigations.”

The researchers indicate that certain professionals (e.g., airline pilots) have rest requirements. But Križan adds that implementing sweeping regulations like this is able to be difficult to do with police departments, that are locally managed. They do not have a national regulator just like the Federal Aviation Administrator or American Medical Association.

He adds that these issues usually are not unique to law enforcement. Other first responders, including firefighters and emergency medical technicians, often experience disruptions to sleep, long shifts and being overworked, and are similarly managed at the town or county level. Križan says an answer might be adding more staff to alleviate first responders, but that comes with additional hurdles, including approval for larger budgets and finding qualified candidates.

While easy policy solutions remain elusive, Križan and his team are continuing to research how poor sleep affects the flexibility of cops to evaluate the credibility of interview subjects. They’re also investigating how individual characteristics may make someone roughly sensitive to the antagonistic effects of fatigue.

Source:

Journal reference:

Krizan, Z., et al. (2023). The impact of alertness vs. fatigue on interrogators in an actigraphic study of field investigations. Scientific Reports. doi.org/10.1038/s41598-023-32975-w.