What is one row?
Complaint, incident, offense, victim, arrest, and call for service are different units. One event may create several rows.
Public data needs a reading guide.English + Español · no account required
Bilingual guideEN / ES
LEARN THE LEDGER / A SELF-GUIDED START
Read the record.
Question the system.
Crime data becomes useful when you know what was counted, who published it, which place and period it covers, and what the number cannot prove.
CHOOSE A QUESTION. FOLLOW THE CONTEXT. VERIFY THE SOURCE.START WITH YOUR QUESTION
What do you want to understand?
01
What is happening near me?
Open an interactive city map, choose one category, and read one reporting area inside a consistent local system.
Explore a map →02Has the pattern changed?
Use a trend only when full-year and partial-year periods are clearly separated.
Read a trend →03What is being counted?
Identify whether the source counts complaints, incidents, offenses, victims, arrests, or calls for service.
Check the unit →04Can two cities be compared?
Check record unit, period, geography, category definition, and denominator before interpreting a difference.
Open comparison →05Why is a map unavailable?
Some official sources publish only citywide values. The Ledger leaves unsupported neighborhood detail visibly unavailable.
Review city coverage →06Who shapes the local system?
Explore city councils, public officials, influence records, and the publication rules for public-integrity matters.
Open integrity desk →FIVE CHECKS BEFORE REPEATING A NUMBER
Every responsible reading carries context.
A number without these five fields is a fragment. The Ledger keeps them visible so you can decide what the record actually supports.
When did it happen?
Year to date, a full calendar year, a month, and a rolling period should not be silently compared.
What place does it represent?
Neighborhoods, police districts, precincts, council districts, and city limits divide communities differently.
Count or rate?
A raw count shows published volume. A rate divides by a trustworthy population or exposure measure.
Who published it?
Read the source owner, last reporting date, update cadence, revision policy, and known missing fields.
COMPARISON SIGNALS
Not every difference is a ranking.
Comparable
Units, periods, geography, and definitions are sufficiently aligned for a careful side-by-side reading.
Use caution
The measures are related, but one or more important definitions differ and must stay visible.
Not responsibly comparable
The records answer different questions. The Ledger shows the limitation instead of manufacturing a score.
PLAIN-LANGUAGE GLOSSARY
Search the words behind the numbers.
16 terms shown
An allegation or event recorded by a police agency. It is not a conviction.
Denuncia policialA reported event grouped under one incident or case identifier.
IncidenteA classified violation attached to a report. One incident may contain several offenses.
Delito registradoA person or entity recorded as affected by an incident or offense.
VíctimaA police enforcement action. It is not a finding of guilt.
ArrestoThe number of published records without adjustment for population or exposure.
Recuento brutoA count divided by a defined denominator, often population, and usually scaled.
TasaThe period from January 1 through the latest complete reporting date.
Acumulado del añoA moving window, such as the most recent six months, rather than a calendar year.
Período móvilThe FBI National Incident-Based Reporting System, which records detailed incident and offense information.
NIBRSThe FBI Uniform Crime Reporting program and its standardized reporting frameworks.
UCRAn administrative service area defined by a police department.
Distrito policialA named local area; official statistical boundaries may differ from everyday usage.
BarrioA saved and checked source extract used when a live endpoint is unavailable or unstable.
Captura verificadaA view limited to what the official source can support without estimation.
Limitado por la fuenteThe population, exposure, or other base used to calculate a rate.
DenominadorTHE CITY SOURCE PASSPORT
Know the dataset before the headline.
Every city should answer the same source questions, even when its data system is different.
Which police department, city agency, or official portal publishes it?
What is the last complete reporting date?
Hourly check, daily source, monthly file, or verified snapshot?
What does one published row represent?
Citywide, neighborhood, district, precinct, beat, or another boundary?
Which records, fields, dates, or areas are missing or incompatible?
TRY IT NOW
Three guided ways into the Ledger.
Choose one neighborhood
Open New York City, change one category, select one area, and read the raw-count warning before interpreting the rank.
Start the map lesson →Test whether two numbers belong together
Open Compare Cities and read the compatibility verdict before the totals.
Start the comparison lesson →Learn from what is missing
Open San Juan and see why citywide facts are preserved without inventing a neighborhood distribution.
Start the source lesson →