Violent offenses reported to Cook County sheriff fall from 541 to 120

Violent crime reported to the Cook County Sheriff's Office fell 77.8% from January through June 2026, compared with the same months of 2025, according to monthly crime data. That drop is far steeper than the statewide decline of 29.3% and the national decline of 6.9%.

In raw counts, the Sheriff's Office reported 541 violent offenses from January through June 2025 and 120 in the same stretch of 2026. Property crime reported to the office fell 38.0%. That was also faster than in Illinois, down 28.7%, and the U.S., down 10.7%.

For suburban Cook residents, that looks like good news. But the figures are preliminary, and a drop this large in a single year should be read as a signal to watch, not a settled fact.

The picture is also uneven across the suburbs. In Arlington Heights, the violent crime rate rose 10.5%. In Alsip, it fell 47.4%.

Faster than the state and the nation

These numbers cover only incidents reported to the Sheriff's Office itself. Arlington Heights and Alsip are tracked separately in the data.

Crime fell almost everywhere this year, so the question is pace. On violent crime, the Sheriff's Office decline of 77.8% outran Illinois and the country by a wide margin. On property crime, the office's drop of 38.0% was also larger than the state and national declines, though the gap was smaller.

The chart below tracks the monthly violent crime rate for the Sheriff's Office, Illinois and the U.S. from January 2025 through June 2026. It shows whether the Sheriff's line moves with the state and the nation, or apart from them.

The national backdrop is a long decline. A Council on Criminal Justice study of large cities found that the drop in reported crime, which began in the second half of 2022, has continued into 2026 (Council on Criminal Justice).

In the cities CCJ tracked, reported homicides fell (Council on Criminal Justice), and so did robberies and carjackings (Council on Criminal Justice). Motor vehicle thefts dropped (Council on Criminal Justice), along with residential burglaries, nonresidential burglaries and larcenies (Council on Criminal Justice).

Not every category improved. CCJ found aggravated assaults and gun assaults down, but reported domestic violence incidents and sexual assaults up (Council on Criminal Justice).

The study is based on a sample of large American cities (Council on Criminal Justice). It is national context, not a measure of what is happening in Cook County.

The council sees broad forces at work. "Local policies and programs surely matter, but the striking consistency of the decline suggests that macro-level forces are exerting enormous influence as well," the council said (Council on Criminal Justice).

Arlington Heights and Alsip go different ways

Arlington Heights moved against the tide. Its violent crime rate rose 10.5% while Illinois and the nation saw declines. The village reported 19 violent offenses from January through June 2025 and 21 in the same months of 2026.

That increase amounts to a small number of incidents. With counts this low, a few cases either way can swing the percentage sharply, so the rise does not by itself show a lasting trend.

Alsip went the other direction. Its violent crime rate fell 47.4%, a steeper decline than both the state and the nation. The village reported 19 violent offenses from January through June 2025 and 10 in the same months of 2026.

The same caution applies. Alsip's drop is real in the data, but small numbers make big percentages. The chart below sets both villages and the Sheriff's Office against the Illinois and U.S. changes. It compares trends and does not rank which place is safer.

Why caution, and what to watch

The data shows what changed, not why. It cannot say whether the Sheriff's Office drop reflects fewer crimes, changes in how incidents were recorded, or gaps in what was submitted.

There are known weak spots in early crime data. CCJ cautions that preliminary incident data for some jurisdictions may have been affected, and that its findings may differ from counts the FBI releases later (Council on Criminal Justice).

Classification errors also happen in Illinois. A review of the state's crime reporting found real incidents submitted by Illinois agencies in 2024 that were determined to have inaccurate offense information (Index). Errors like that can shift counts between categories.

Residents should watch whether the Sheriff's Office's monthly numbers stay low once July through December 2026 figures arrive. They should also watch for revisions to the early-2026 data, and for whether Arlington Heights and Alsip hold their direction over a longer period.

If the Sheriff's decline holds up in final counts, it would mean the areas it covers are easing faster than the state and nation. If it shrinks after revisions, the more modest statewide and national declines may be the better guide.

How we did this

We used monthly crime data for the Cook County Sheriff's Office, Arlington Heights, Alsip, Illinois and the United States. For each, we added up the monthly population-adjusted violent and property crime rates for January through June 2026 and compared that total with the same months of 2025. We also report raw offense counts, such as the Sheriff's Office's 541 violent offenses in early 2025 and 120 in early 2026.

Violent crime: offenses such as murder, rape, robbery and aggravated assault. Property crime: offenses such as burglary, larceny-theft, motor vehicle theft and arson. Crime rate: the number of reported offenses adjusted for population, so places of different sizes can be compared. Percent change here: the difference between the summed monthly rates for January through June 2026 and the same months of 2025.

Limitations

• The monthly figures are preliminary and can be revised as agencies update or correct their submissions.
• The data shows how much reported crime changed, not why. Crimes never reported to police are not counted.
• Arlington Heights and Alsip have small violent crime counts, so a few incidents can produce large percentage swings.
• The Sheriff's Office figures cover only incidents reported to that agency.
• The Council on Criminal Justice study covers a sample of large cities and is national context, not a measure of Cook County.
• Offense classification errors in agency submissions can shift counts between crime categories.

Sources

• Federal Bureau of Investigation, Crime Data Explorer: Cook County Sheriff's Office: violent crime, monthly, 2024-11 to 2026-10, latest period September 2026, released Sept. 15, 2026; retrieved Oct. 14, 2026. Data
• Federal Bureau of Investigation, Crime Data Explorer: Cook County Sheriff's Office: property crime, monthly, 2024-11 to 2026-10, latest period September 2026, released Sept. 15, 2026; retrieved Oct. 14, 2026. Data
• Federal Bureau of Investigation, Crime Data Explorer: Arlington Heights Police Department: violent crime, monthly, 2024-11 to 2026-10, latest period September 2026, released Sept. 15, 2026; retrieved Oct. 14, 2026. Data
• Federal Bureau of Investigation, Crime Data Explorer: Alsip Police Department: violent crime, monthly, 2024-11 to 2026-10, latest period September 2026, released Sept. 15, 2026; retrieved Oct. 14, 2026. Data