Decades ago, Richfield police took a risk, becoming one of the first five law enforcement agencies in Minnesota to assign officers to 12-hour shifts.

With the lengthy shifts came impressive payoffs — a calendar filled with more time off, including three- or four-day breaks to catch up on sleep, help out at home or socialize.

"We've been doing it for 25 years now," said Deputy Chief Mike Koob of the Richfield Police Department. "I think we'd have a revolt if we ever went back."

Over the past 10 to 15 years, other Minnesota police departments slowly began making the switch to longer shifts over fewer days.

Inver Grove Heights, Blaine, Lakeville and Ramsey police went to 12-hour shifts in the past six years. Hastings cops will do so next year.

"It's becoming more commonplace in law enforcement," said Lt. Brian Tholen of the Edina Police Department. "It's nice to have the time for officers to go home and spend quality time with their family."

No one tracks police schedules statewide. An informal phone survey found metro-area departments divided between 10- and 12-hour schedules, though some have hybrid shifts. West St. Paul police work a 9½-hour schedule. Cottage Grove will shift from 10½ hours to 11 hours next year.

In Minneapolis, officers work either eight or 10 hours, depending on their job. St. Paul police put in 10-hour shifts.

Most police officials say the officers prefer the arrangement over a conventional eight-hour day, citing improved mental health, increased productivity and more coverage during peak times.

But not everyone is a fan. Lurking behind its appeal are worries about fatigue, which some studies and sleep experts say could hamper judgment or lead to accidents in a profession with high stakes.

"The longer you work, the more it's going to impact your potential sleep," said Dr. Michael Howell, a University of Minnesota neurologist. "For police officers, the question is also life and death."

Research results mixed

The Minnesota Chiefs of Police Association and Law Enforcement Labor Services — Minnesota's largest police union — have taken no position on the issue. Schedules don't usually affect contract negotiations, union officials said.

Duty rotations can be complex and vary by department.

A 550-page, three-ring binder filled with sample schedules sits on the desk of Capt. Greg Rinzel of the Cottage Grove Police Department, demonstrating how many options exist. "It's been studied almost to the point of nauseam," Rinzel said.

Research has reached mixed conclusions. A 2011 study by the Police Foundation, a nonprofit research organization, compared experiences of officers in Detroit and Arlington, Texas, who were randomly assigned eight-, 10- and 12-hour shifts. The study found that officers working 10 hours performed better on measurable tasks. Those working 12 hours said they were sleepier and less alert at work than those working eight hours. Even so, the authors found that the longer schedules "do not raise significant concerns."

A study published in 2008 by Police Chief magazine (the International Association of Chiefs of Police periodical) examined the results when part of the Lincoln Police Department in Nebraska switched to 12-hour shifts. Most measures, from productivity to discipline rates, remained the same. Every officer preferred the longer schedule, and the study concluded that 12-hour shifts were a "viable scheduling alternative."

Yet while all of the officers said they could perform under the schedule, 13 percent acknowledged there had been times when they couldn't function safely.

That's what concerns Chief Bud Shaver in West St. Paul.

"I wouldn't consider going to a 12-hour shift," Shaver said. "After an extended work period, an officer's work performance and decision-making skills tend to diminish."

There are other snags. Court days can become complicated, especially when an officer works 12 hours, gets off at 6 a.m., and has court the next morning or afternoon. "Your sleep gets broken up," said Sgt. Jeff Warner of the Blaine Police Department.

Officials said long shifts mean that on workdays, officers must accept that there's only time for work and sleep.

Work-life balance

Nearly everyone interviewed by the Star Tribune said that while there are downsides, the pluses of longer shifts outweigh the minuses. Officials from eight departments said they don't believe their schedule results in overtired officers. Many said they monitor the issue.

Before Elk River police debuted 12-hour shifts in 2004, Chief Ron Nierenhausen said skeptics predicted that officers would take more sick days and be less productive. That didn't happen, he said.

Nierenhausen said officers are polled yearly about the schedules, and they opt to stay with 12-hour shifts.

Longer shifts mean more officers on the street when they're needed, said South St. Paul Chief William Messerich, whose department started the arrangement in 2005. He said other shift schedules sometimes resulted in officers doubled up in squad cars unnecessarily. The 12-hour shifts make it easier for most officers to achieve a good work-life balance, Messerich said.

"There have certainly been officers that have difficulty with their 12-hour shifts," Messerich said. "It balances out though — an off day is just around the corner."

The Inver Grove Heights City Council heard a presentation by then-Interim Chief Sean Folmar in early December summarizing the department's first year with 12-hour shifts. Folmar listed benefits of the system, including boosted morale, having a supervisor on duty 24 hours a day and more efficient training because the department can train in two days instead spreading it over five days as before.

Residents have asked if the department hired more officers, noting they're more visible now, Folmar said.

Officer-initiated activities — checking on suspicious cars, traffic stops, patrolling crime hot spots — are up 144 percent to 8,959 in 2017 from 3,671 in 2016. Folmar said the only drawback is that officers use less vacation time.

Police officials caution that what works for one department might prove ineffective elsewhere, depending on department size, call volumes and organizational culture.

"Every city is unique," said Sean Gormley, Law Enforcement Labor Services' executive director. "Once an agency finds something that works, it's hard to break that up."

Erin Adler • 612-673-1781