Lower West Side Crime Rate Trends — Chicago
Lower West Side — also known as Pilsen — is a Near West Side neighborhood organized around 18th Street and Blue Island Avenue. Anchored by the National Museum of Mexican Art, the Thalia Hall venue, and a long-standing concentration of public murals; bordered by the South Branch of the Chicago River.
Two signals surfaced in Lower West Side this August, both pointing at the same category. Sexual assault registered both a one-month spike and a sustained multi-month structural shift, meaning the rise is not just a single noisy month but a pattern that has built across the trailing 12 months.
The 12-month total for sexual assault is now 59 incidents, up from 28 in the prior 12-month period, a 110.7% increase year over year. Every other tracked category stayed within its normal range this month. Robbery is the one clear counterweight in the data, down 25.6% over the same window, 61 incidents against 82 the prior year, but that decline does not offset the direction of the sexual assault trend.
Notable signals 1
Sexual Assault
The past 12 months saw 59 incidents — about 109% above the 28 average from prior years.
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.
- Sexual Assault is climbing.
The trailing 12-month count is 59, up 111% from 28 the year before. If the trend holds another quarter, it will pull the multi-year baseline up.
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 Lower West Side compares
Peer neighborhoods picked by closest 12-month sexual assault 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 sexual assault levels.”
Auburn Gresham
57 incidents over the past 12 months — 2 below Lower West Side's 59.
Open page →Roseland
56 incidents over the past 12 months — 3 below Lower West Side's 59.
Open page →South Lawndale
56 incidents over the past 12 months — 3 below Lower West Side's 59.
Open page →Do crime spikes here spill over to adjacent neighborhoods?
Lower West Sidedoesn't have enough spike history in any single category for a stable spillover rate yet (we want at least 5 events). The table below lists what we have.
| Category | Spike events | Same-category spillover |
|---|---|---|
| Sexual assault | 1 | — too few |
Each row shows Lower West Side's historical spike events for that category, and how often any of its 8 adjacent neighborhoods spiked the same category within the next 3 months. A high same-category rate suggests a shock that travels (e.g. theft crews moving across Chicago); a low rate means spikes here tend to be local to the neighborhood. Categories with fewer than 5 historical spike events are listed but their rates are suppressed.
Recurring local terms (last 12 months)
Top terms in incident descriptions for Lower West Side, 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.