Chatham Crime Rate Trends — Chicago
Chatham is a South Side neighborhood organized around 79th and 87th Streets, bordered by the Chicago Skyway and the Dan Ryan Expressway. Predominantly single-family bungalows; anchored by Cole Park, Tuley Park, and the 79th Street commercial corridor.
August 2026 produced a single notable signal in Chatham: robbery has shifted structurally downward, not just in one quiet month but across a full 12-month window. With only one sustained-shift signal and no spikes, drops, or rare events elsewhere, the month's shape is narrow, one category driving the story against an otherwise stable backdrop.
Robbery fell 29.3% against the prior 12 months, 147 incidents versus 208 the year before. That is a multi-year structural move, not a one-month fluctuation. Every other tracked category stayed within range, with vandalism down 9.8% (586 vs. 650) and other larceny down 18.9% (924 vs. 1,139) adding to a broadly softer picture on property crime, though neither crossed the anomaly threshold this month. Arson ticked up to 12 from 8, a 50.0% year-over-year change, but at those volumes the move is too small to treat as a reliable trend.
Notable signals 0
Nothing notable surfaced this month — every category sits within normal range against its baseline.
All categories, last 24 months
Each panel: recent monthly count vs. trailing 12-month context. MoM is the most recent month vs. the one before; 12mo YoY compares the trailing year to the year before that.
What's been quietly true for a year
Spikes get attention. Sustained shifts shape policy. These are multi-quarter patterns where the past 12-month total differs meaningfully from the year before — they often precede the baseline resetting.
- Robbery has reset to a lower baseline.
The trailing 12-month count is 147, down 29% from 208 the year before. If the trend holds another quarter, it will pull the multi-year baseline down.
What next month likely looks like
Forecasts trained through August 2026, with a likely range we're 95% confident the actual count will fall inside. Categories with too little recent volume — or violent categories at the neighborhood level — show no forecast and are surfaced through signals above instead. See the methodology page for the gating rules.
Aggravated Assault
Too low-volume per neighborhood for a reliable point forecast — see the rare-event and streak-break signals above instead.
Arson
Below the volume threshold for a reliable forecast — too few incidents in recent months to project from.
Burglary
Homicide
Too low-volume per neighborhood for a reliable point forecast — see the rare-event and streak-break signals above instead.
Motor Vehicle Theft
Other Larceny
Robbery
Too low-volume per neighborhood for a reliable point forecast — see the rare-event and streak-break signals above instead.
Sexual Assault
Too low-volume per neighborhood for a reliable point forecast — see the rare-event and streak-break signals above instead.
Vandalism
How Chatham compares
Peer neighborhoods picked by closest 12-month robbery volume — a pragmatic v1 of peer matching. Demographic / housing-stock peer matching isn't built yet (we deliberately don't ingest income or race data alongside crime). Volume similarity has the right intuition: “neighborhoods experiencing comparable robbery levels.”
Roseland
144 incidents over the past 12 months — 3 below Chatham's 147.
Open page →North Lawndale
159 incidents over the past 12 months — 12 above Chatham's 147.
Open page →Greater Grand Crossing
167 incidents over the past 12 months — 20 above Chatham's 147.
Open page →Recurring local terms (last 12 months)
Top terms in incident descriptions for Chatham, excluding generic crime taxonomy. Useful as texture — what kinds of specifics show up here that don't show up elsewhere.
Hour-of-day, day-of-week, and seasonality
Distribution of bucketed incidents in this neighborhood across the full analysis window. Useful for routine context — shopping-strip thefts vs. late-night assaults read very differently when you can see when each typically happens.
How we built this page
Data → Anomalies → Forecast → Page
Incident data is pulled from CPD's open dataset on the City of Chicago Open Data portal — IUCR-coded and mapped to 9 UCR-aligned categories (theft from vehicle isn't reliably separable in the public feed and rolls into other larceny). Aggregated to community area × category × month.Anomalies are surfaced using strict thresholds (~p < 0.01). Forecasts are Prophet with low-count gating; violent categories at the neighborhood level skip the forecast and show rare-event / streak signals instead.
Spike rule: 12-mo total > baseline mean + 2.5σ AND ≥ 20 incidents AND 6-mo confirms. Drop rule: 12-mo total < baseline mean − 2.5σ AND baseline mean ≥ 20. Rare event: any incident in the last 90 days, no prior comparable in ≥ 5 years.