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 March — a one-month spike and a structural sustained shift, both in the same category. That concentration tells a specific story: this is not a broad sweep across crime types, but a single category drawing attention on two separate diagnostic dimensions at once.
Sexual assault is the category in focus. The 12-month total stands at 51 incidents against 23 in the prior year — a 121.7% increase year-over-year. The sustained-shift signal means this is not a single noisy month; the gap between the current trailing 12 months and the prior period has widened enough to register as a structural change. Every other tracked category — robbery down 31.6%, motor vehicle theft down 11.8%, vandalism down 10.6%, homicide and arson each down 57.1% — ran within range or declined, making the sexual assault pattern the sole outlier in an otherwise broadly downward month.
Notable signals 1
Sexual Assault
The past 12 months saw 51 incidents — about 81% 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 51, up 122% from 23 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 March 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.”
Edgewater
50 incidents over the past 12 months — 1 below Lower West Side's 51.
Open page →West Englewood
52 incidents over the past 12 months — 1 above Lower West Side's 51.
Open page →Englewood
53 incidents over the past 12 months — 2 above Lower West Side's 51.
Open page →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 SFPD's open dataset, mapped to 10 NIBRS-aligned categories, and aggregated to neighborhood × 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.