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.
September 2026 was a quiet month in Chatham. No tracked category crossed the anomaly threshold, and the signal count for the month is zero. The story here is structural, not episodic: the 12-month totals show a broad, multi-category pattern that has been building across the prior year.
Homicide is down 42.9% over the trailing 12 months, 8 incidents against 14 in the prior year. Robbery is down 20.9% (151 vs 191) and other larceny is down 17.5% (945 vs 1,146). On the other side, arson is up 44.4% on a small base, 13 incidents against 9, and sexual assault edged up 10.5% (42 vs 38). Aggravated assault and burglary are each within a few percent of prior-year levels. The month produced no single-month deviations worth isolating, but the 12-month arc is one of declining violent crime and larceny alongside modest increases in a few lower-volume categories.
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.
No sustained shifts surfaced this month.
What next month likely looks like
Forecasts trained through September 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 other larceny 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 other larceny levels.”
Greater Grand Crossing
909 incidents over the past 12 months — 36 below Chatham's 945.
Open page →Edgewater
891 incidents over the past 12 months — 54 below Chatham's 945.
Open page →Auburn Gresham
1,008 incidents over the past 12 months — 63 above Chatham's 945.
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.