Hennepin County is considering several changes to its jail policies to reduce the time inmates are locked up.

Early last year, Sheriff Rich Stanek sent a letter to county commissioners warning that the jail population had surged to record levels and was constantly at capacity. That potentially put staff and inmates at risk, and overtime costs were through the roof.

This year, the County Board commissioned a study to examine the jail’s population over 18 months and recommend ways to reduce it. On Thursday, retired Hennepin County judges John Stanoch and Lucy Wieland, who guided the project, presented their findings to the board and the county’s top criminal justice leaders.

Commissioners were told that there wasn’t a single “silver bullet” explanation for the significant increase in jail population for 2017 and the decrease that followed in the summer of 2018. The jail’s daily population this week is at 682, down from 885 in April 2017.

Instead, four major drivers of jail population were studied: bookings, pretrial release, length of stay and alternatives to detention. Some suggested changes include the creation of an integrated criminal justice information system, more electric home monitoring, earlier release before charging, lower bails for people booked and released, and shorter stays for minor probation violations.

“A jail is not like a hotel where you can just put up a no-vacancy sign,” said Wieland.

Hennepin County has two jails in downtown Minneapolis, one at City Hall and the other just across the street. The combined total of beds is 839, but 10 percent of them are reserved for inmates who need be separated from the rest of the population, so the actual number of daily beds available is 755.

The jail has 307 employees, and its budget for 2018 is $39.5 million. When its population surged in 2017, it cost the county $1.5 million in overtime. For every 25 inmates over capacity, the cost is $250,000 a year.

Earlier this week, an inmate escaped from the jail at the Hennepin County Public Safety Facility and was quickly recaptured, the first such escape from the facility since it was built in 2001.

The county took bids to run the study, and one bid came in at $234,000, said Mark Thompson, assistant county administrator for public safety. The bill for Stanoch and Wieland, who volunteered much of their time, will be under $30,000, he said.

During the two-hour presentation, Wieland joked that she initially thought the study would be easy to complete. However, the lack of an integrated county criminal justice data system, and different data management systems for various partners in the justice system, made analysis extremely difficult, she said.

The jail population drivers delivered some meaty statistics for the County Board to ponder and debate. On bookings, the study found an increase in the number of people brought to jail for probable-cause holds. Those are inmates arrested but not charged; they can be held up to 48 hours.

Pretrial release, another population driver, triggered a robust discussion on the effectiveness of the risk-assessment tool probation officers use to decide if an inmate can be let out. Hennepin County releases 84 percent of inmates before trial, significantly higher than the national average.

“Risk assessment tools are controversial throughout the country,” said Mary Moriarty, chief public defender for Hennepin County. “We need to remove the subjectivity.”

The most troubling statistic was the jump in the length of time inmates stay in jail. The average stay rose from 5.8 days in 2015 to 20.1 days in 2017. The county is already trying to remedy the issue through lower bail requests by the county attorney’s office and the assignment of two more judges to expedite the handling of felony cases.

A few factors in lowering the jail population this summer were quicker court hearings and presentence and mental health evaluations, along with speedier jail transports by the Sheriff’s Office, Thompson said.

Stanoch said the most important change the study suggested was creation of a public safety data information system. This would allow the courts, corrections employees and the jail to communicate about who is in custody in real time, he said. The same system was recommended by county officials in 1998, around the time the jail was built, but it was rejected because it was believed a new statewide data system could be integrated with Hennepin County.

The proposal would also include the hiring of a data scientist, which the board voted on Thursday.

Another idea is to reduce the number of inmates at the jail who violated their supervised release conditions. The state Department of Corrections can hold them pending a hearing on the violation.

The study suggested housing the inmates at the workhouse in Plymouth or placing them on electronic home monitoring. This would save nearly 80 beds a night.

“The jail averages 30 inmates on these holds each night and the cost to house an inmate is $140 a day,” said County Commissioner Linda Higgins — an annual bill of more than $1.5 million. “Maybe we should send the Department of Corrections a bill.”

Because 50 percent of the people arrested on a probable-cause hold don’t get charged, the study suggested ways to get them out of jail more quickly. Changing bail amounts was also considered, with Board Chair Jan Callison requesting that a resolution be presented to the board.

Finally, an oversight committee with representatives that have decisionmaking authority was proposed.

Thompson reminded the board that Hennepin County has had the lowest pretrial jail population in the United States for the last 20 years. “But that doesn’t mean we should take our foot off the gas,” he said.