Nearly 1,900 immigrants were detained during the first half of Operation Midway Blitz. Most had no criminal record.

Newly released federal data shows that immigration agents booked in roughly 1,900 immigrants in the first half of Operation Midway Blitz — two-thirds of whom had no known criminal convictions or pending charges.

The latest data offers the first comprehensive look at the effects of the operation, and a Tribune analysis underscores the divide between the stated goal of the administration of President Donald Trump — to target “the worst of the worst” — with the reality of controversial roundups that typically snagged immigrants living in the the U.S. without permanent legal status even though they had no known rap sheets.

Of the 1,895 people detained by ICE, 1,271 lacked any criminal record. Another 343 people arrested had a pending criminal charge, while 281 had a criminal conviction. Of those with a criminal conviction, the vast majority of offenses were misdemeanors, traffic citations or nonviolent felonies. Only 28 arrestees —1.5% — had been convicted of a violent felony or sex crime.

The U.S. Department of Homeland Security, which ran the operation, did not dispute the analysis. In a statement Tuesday, it said that across the country most of those detained had criminal convictions or pending charges as it targets “the worst of the worst criminal illegal aliens —  including murderers, rapists, and pedophiles.”

It previously has argued that the Trump administration, while targeting dangerous “illegal aliens,” welcomed the arrest of anyone in the United States without legal status, no matter how otherwise law-abiding they were.

The agency argued in a past news release that its efforts collectively helped lower crime as part of what it called “a historic win in the fight against violent criminal illegal alien crime.” The boast, however, ignored several consecutive years of decreases in Chicago’s violent crime.

The findings come from a Tribune analysis of updated U.S. Immigration and Customs Enforcement data obtained and shared Monday by the research group Deportation Data Project.

Unlike typical law enforcement agencies, ICE does not release complete lists of those arrested, but the agency periodically has been forced to release raw data of its activities under an open records lawsuit. That data has helped document the dramatic escalation of enforcement efforts in Chicago and across the country, although it doesn’t list enough details to make precise measurements of specific enforcement actions.

The best window into local impacts of Operation Midway Blitz appears to come from tallying those immigrants living in the U.S. without permanent legal status who were booked into either of two Chicago area ICE facilities — a main temporary holding jail in west suburban Broadview and an office in the South Loop. And those figures show 1,895 people booked into either facility between Sept. 8, the announced start of Operation Midway Blitz, and Oct. 15, the most recent data available.

Because some detainees were booked multiple times, ICE recorded a total of 1,912 bookings in that period — a significant boost in the pace of detentions that steadily climbed to an average of nearly 70 a day by mid-October. That’s roughly double the arrest rate in early June, the most intense immigration enforcement period prior to Operation Midway Blitz.

Nearly all the bookings occurred in Broadview, under the shadow of regular, sometimes confrontational protests. The nondescript building — a way station with large holding cells meant for stays less than 12 hours — rarely saw more than a handful of bookings a day under the waning days of the administration of President Joe Biden. Since Trump regained office, the facility at times has seen more than 100 people jammed there for days without beds, showers or hot food, which sparked a federal lawsuit alleging inhumane conditions.

Still, those figures may not capture those arrested and booked into another facility outside the region. DHS has broadly defined the boundaries of Operation Midway Blitz, including arrests in northwest Indiana, for example. By DHS’ calculations, agents had arrested more than 4,300 during the operation “including rapists, murderers, and gang members.”

In its Tuesday statement, the agency did not break down how many of those arrested lacked any criminal records before their arrest but cautioned that such breakdowns may miss detainees who lack rap sheets in America but have them in their home countries or others outside the United States. The agency, however, did not provide any information about how many detainees had been accused of crimes in their home countries or elsewhere.

Immigrant advocates said the new numbers confirm what they have been hearing from families and volunteers since the start of the operation.

Erendira Rendón, vice president of immigrant justice at The Resurrection Project, said her organization, along with others, has been interviewing affected families and tracking detentions in real time.

“This data proves what we have known all along: This wasn’t about catching criminals. It was about targeting our people based on the color of our skin,” Rendón said. “Immigrants are our people: hardworking, law-abiding families who deserve to live beautiful and full lives free from the fear of being kidnapped by masked men.”

Though the operation, led by U.S. Border Patrol Cmdr. Gregory Bovino, has ended, advocates say immigrants across the region, whether or not they have permanent legal status to live in the country, continue to feel as if they are living under siege.

“Bovino and his ‘gang’ may be gone for now, but our community is still reeling from the assault, still counting the people who’ve been disappeared from our lives, still bracing for the next wave. We can’t truly heal until we’re no longer living under the constant threat of their return,” she said.

Brandon Lee of the Illinois Coalition for Immigrant and Refugee Rights said the figures underscore DHS’ lack of transparency about the operation, noting that the agency has not provided a breakdown of arrests or disclosed where many detainees were taken. They said the newly released numbers further support allegations that agents used unconstitutional tactics, racially profiling Latinos, “arresting first and asking questions later.”

“Trump and other MAGA-aligned officials have long targeted Chicago and Illinois for living out our welcoming values, and we knew from the start that this administration would be targeting our communities, including citizens and noncitizens alike,” Lee said. “The numbers are jarring but unsurprising, and it sounds an alarm that goes beyond our state.”