Armour Square sexual assault moved sharply above its multi-year baseline this month, the most prominent fresh signal in Chicago's May 2026 briefing. Hegewisch vandalism had topped the rankings last month, but the same-category pattern across prior briefings earns it the backdrop role this time — the leading story is a different crime type in a different neighborhood.
Citywide volume is down 6.5% against the prior 12 months — 130,966 incidents versus 140,093. The mix carries more spikes than a typical down month: 13 fresh spikes alongside 68 sustained-shift signals and 31 below-trend signals. Gage Park other-larceny and Lower West Side sexual assault both appear in the top five, and Hegewisch vandalism remains elevated even as it cedes the lead position.
The Armour Square sexual assault signal is new to the top of the rankings — this is the first month it has appeared there. The broader citywide decline holds, and 68 of the 113 tracked signals reflect sustained downward movement across 77 neighborhoods. The spike cluster in May is narrow enough that it doesn't reverse the structural trend, but sexual assault appearing twice in the top five — Armour Square and Lower West Side — is a pattern to track into June.
Sustained drops worth naming
Robbery ran below trend in the trailing 12 months — 33% down from the year before. Sustained shifts often precede a baseline reset; we surface them at the same prominence as spikes.
How last month's forecasts performed
Forecasts for May were issued from data through April 2026. 9 of 9 citywide bucket forecasts (100%) landed inside their 95% prediction intervals.
| Category | Predicted | Actual | Error | In CI |
|---|---|---|---|---|
| Aggravated Assault | 1157[1037–1285] | 1182 | 2.1% | INSIDE |
| Arson | 41[25–57] | 32 | 27.9% | INSIDE |
| Burglary | 564[381–745] | 454 | 24.2% | INSIDE |
| Homicide | 44[25–63] | 37 | 19.6% | INSIDE |
| Motor Vehicle Theft | 1912[998–2811] | 1658 | 15.3% | INSIDE |
| Other Larceny | 5367[4354–6422] | 5646 | 4.9% | INSIDE |
| Robbery | 426[201–655] | 401 | 6.3% | INSIDE |
| Sexual Assault | 271[238–306] | 280 | 3.1% | INSIDE |
| Vandalism | 2281[2069–2504] | 2250 | 1.4% | INSIDE |
Per-bucket coverage, MAPE, and bias across the full 12-month horizon live on the methodology page.
Public Analyst.ai, “May 2026 — Chicago,” archived snapshot.Permanent URL: /chicago/2026/may