Treasure Island Crime Rate Trends — San Francisco
Treasure Island is a manmade 400-acre island in San Francisco Bay, built for the 1939 Golden Gate International Exposition and later used as a U.S. Navy base until 1997. Today it is a small residential community and event venue under long-term redevelopment, connected to the city by the Bay Bridge.
Two signals emerged in Treasure Island this September, one below-trend single-month drop in burglary and one zero-event category, against a backdrop of broad, multi-year declines across nearly every tracked crime type. The shape of the month is consistent with a structural downward trend rather than a one-off quiet stretch.
Burglary is the month's clearest signal: 13 incidents in the trailing 12 months against 29 in the year before, a 55.2% reduction. The broader context reinforces that: aggravated assault is down 64.3% year-over-year (5 incidents vs. 14), other larceny is down 45.2% (17 vs. 31), and vandalism has fallen 33.3% (30 vs. 45). Motor vehicle theft is the one category holding roughly flat, down just 3.4%. Everything else is running well below where it was a year ago.
Notable signals 1
Burglary
The past 12 months saw 13 incidents — about 67% below the 40 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.
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
Below the volume threshold for a reliable forecast — too few incidents in recent months to project from.
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.
Theft from Vehicle
Below the volume threshold for a reliable forecast — too few incidents in recent months to project from.
Vandalism
How Treasure Island compares
Peer neighborhoods picked by closest 12-month burglary 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 burglary levels.”
Japantown
20 incidents over the past 12 months — 7 above Treasure Island's 13.
Open page →Seacliff
6 incidents over the past 12 months — 7 below Treasure Island's 13.
Open page →Portola
21 incidents over the past 12 months — 8 above Treasure Island's 13.
Open page →Recurring local terms (last 12 months)
Top terms in incident descriptions for Treasure Island, 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 on DataSF, 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.