Early in the morning outside Cook County Jail, a group of new detainees stepped out of a Chicago police wagon and walked bleary-eyed into the bright sunlight before lining up inside against a brick wall.

Brought in from the police districts, the men were among the newest bookings to the jail, where they would wait until a judge ruled on whether they would be admitted or released while their charges were pending.

And the jail, busy during the early morning hours as police brought in overnight arrestees and deputies shuttled detainees to court appearances, may only grow more bustling: After a decline following statewide bail reform — and years of reductions prior to that — the county’s jail population has begun to tick up once again.

In an internal report obtained by the Tribune via a public records request, the Cook County sheriff’s office found that the average daily jail population has risen by about 12% in recent months, reaching its highest level in eight months at the end of March.

The report also found sharp increases in detention for some charge types for which State’s Attorney Eileen O’Neill Burke has implemented policy changes.

Many factors can influence the ebb and flow of the jail’s population, and experts pointed to a number of potential considerations when evaluating it, including arrest rates and judicial decision-making.

The sheriff’s office’s analysis, the report said, sought to understand the impact of the policies of Burke, who was ceremonially sworn in on Dec. 2.

Sheriff Tom Dart, in an interview with the Tribune, made clear that he supports policies that keep high-risk defendants incarcerated, but said he is concerned about how long inmates remain in jail as court cases move sluggishly through the system.

The county jail is meant to be a temporary waypoint for defendants until their case is finished, and lengthiness of proceedings can contribute to jail population levels.

In other quarters, the jail’s spike raised questions about whether prosecutors were considering the nuance of cases amid Burke’s more hardline detention policies than her predecessor Kim Foxx, who was elected in 2016 with a reform mandate on a wave of anger over the killing of 17-year-old Laquan McDonald by a Chicago police officer.

But Yvette Loizon, chief of policy at the state’s attorney’s office, said that prosecutors are only one piece of the detention mechanism.

“When people want to lay the uptick in the jail population at our feet, that’s a fundamental misapprehension of the process,” she said, adding that judges ultimately make the decision and defense attorneys can offer evidence that refutes or mitigates the need for jailing.

“I would submit that because we are doing a better job of presenting relevant and necessary and important information to the judiciary … judges have more information and better information upon which to make the decision.”

Regardless of political viewpoints on detention, the rising jail numbers have not gone unnoticed by city and county stakeholders, as the phenomenon — especially if it continues into the traditionally more violent summer months — could come with complications such as cost increases and more difficulty with crowd management.

“It’s probably not a simple explanation,” said David Olson, co-director of Loyola University Chicago’s Center for Criminal Justice Research.

Since the 2010s, the county’s jail population has fallen significantly, cut nearly in half from typical average populations around 10,000 in that era.

It started decreasing after Evans in 2017 reformed county policies around bail and was reduced further after the Pretrial Fairness Act in September 2023 eliminated cash bail in Illinois.

After the measure took effect, the jail numbers fell to under 5,000 for much of 2023 and 2024, reaching levels not seen since the height of the COVID-19 pandemic when some lower-risk inmates were diverted from the jail for public health reasons.

When Burke took office in early December, the jail’s population was around 5,200, having increased slightly at the end of Foxx’s term, according to data from the sheriff’s office.

As of Friday, the population had grown to just over 5,600.

The sheriff’s office plans to produce a monthly analysis with the goal of tracking the impact of Burke’s policies on the jail, according to the first such report in March.

Among the findings of the April report:

Monthly admissions for people ordered detained had increased 47% as of the end of March, compared with admissions during the month prior to the start of Burke’s term.

Admissions for domestic battery and felony retail theft-related offenses saw the largest increases, 81% and 32% respectively, compared with November of 2024.

Olson said the theft-related increase caught his eye because such charges are generally not an offense prosecutors are allowed to seek detention on, though defendants can be detained if there are other charges or violations involved.

“That there’s a big increase in people coming in on a theft charge seems odd because theft offenses are not eligible for pretrial detention at the first stage,” he said. “The fact that those have gone up so much suggests that it might be people who were on pretrial release that then got charged for a new crime that the state is now seeking to detain them.”

During a swearing-in speech last year, Burke announced that prosecutors would automatically ask judges to order defendants detained while awaiting trial if they faced certain charges. By contrast, Foxx’s office had said it reviewed each case individually before making a decision about whether to seek detention.

Burke also reversed a policy by Foxx that raised the threshold to charge retail theft as a felony to $1,000, reverting back to the legal bar of $300. She also has ordered prosecutors to seek prison sentences in more gun cases.

Sharlyn Grace, senior policy adviser at the Cook County public defender’s office, said the city has not experienced rising crime levels to correspond with the increasing jail population.

“I think it does raise a lot of questions about public safety and what the impact is going to be because we know many people who are subject to pretrial detention will come home,” she said. “Research shows that detaining people is going to lead to less employment, less stable housing … a higher likelihood of re-arrest.”

Matthew McLoughlin, campaign coordinator for the Illinois Network for Pretrial Justice, said Burke’s detention policy is contrary to the spirit of reforms to the county’s pretrial system, adding that the group believes it’s the primary driver of the jail’s spike.

“I would say the blanket detention policies that she’s put forward since taking office … are not in line with the goals of the Pretrial Fairness Act,” he said. “It was really designed to make sure court stakeholders were taking time with each individual case.”

Loizon, though, said line prosecutors are presenting judges with a “very thorough and fulsome explanation of the details of the crime.”

“We’re not walking away from our detention policy and the state’s attorney’s office absolutely owns the fact that we are ensuring our ASAs are presenting all the information that they can present so that a judge can make an informed decision based on the relevant facts,” Loizon said.

“We absolutely own that piece of it because that is a priority for us.”