Diamond Bar, CA has a A safety grade (76/100) with a violent crime rate of 78 per 100,000, 78% below the national average.
FBI UCR 2024 · per-capita rates · large city
At 51,126 residents, Diamond Bar is a large city: FBI UCR Table 8 rates (per 100,000) here are read against CA and U.S. averages before the offense-family breakdown.
Data updated 2026-08-24
Diamond Bar, CA carries a PlainCrime A safety grade with violent crime 78% below the U.S. average
According to the FBI Uniform Crime Reporting (UCR) Program for 2024, Diamond Bar, CA shows violent crime at 78.2 per 100,000 residents and property crime at 1,862.1 per 100,000. Violent crime runs 78% below the U.S. average. PlainCrime assigns grade A from those rates. Figures are voluntary agency submissions joined to population denominators; incomplete coverage can move the number.
Position in the state cohort
At 78.2 reported violent offenses per 100,000 residents in 2024, Diamond Bar ranks 438 of 458 — above 20 of the 457 other California cities whose 2024 submission passes this site’s completeness test. That is -76.5% against the cohort median of 333.1. Cities that did not report, or that reported implausibly low totals, are excluded from this cohort rather than counted as low-crime.
Comparable rate records
The nearest comparable 2024 records to Diamond Bar's 78.2 violent-crime rate per 100,000 are Los Altos (77.8), Imperial (77.3), Lafayette (80.2), Rancho Santa Margarita (81.1). These are same-year agency submissions that pass the same completeness screen, not a claim that the cities have identical conditions. They make the cohort position above checkable against named records instead of a generic state average.
Offense mix
Violent offenses are 4.0% of the 992 Part I offenses reported in Diamond Bar for 2024, against a median of 17.1% across comparable California cities — a gap of 13.1 points. Offense mix is shaped by which agencies report and how incidents are classified as well as by the underlying offenses, so it describes the reported record rather than a settled difference in conditions.
2020–2024 direction
Across 4 comparable reporting years, the rate moved from 111.2 per 100,000 in 2020 to 78.2 in 2024 (-29.7%). The highest observed value was 174.5 in 2022 and the lowest 78.2 in 2024. Years whose submission failed the completeness test are left out of this comparison rather than plotted as change.
Property-offense composition
Larceny-theft is 55.9% of reported property offenses in Diamond Bar, against a cohort median of 69.5%. The remainder is burglary (346) and motor vehicle theft (74). Composition differences of this size usually track what kinds of places and property are present in a jurisdiction.
Property counts dominate Diamond Bar's FBI UCR Table 8 municipal row. Per-100,000 rates use the reporting-year population on that row; cities that fail the completeness test stay out of rate rankings. A citywide figure rarely describes any single neighbourhood inside the municipal boundary.
On a large city row, these are citywide reported offense totals - not neighbourhood advice. Conditions vary by place and time; reporting rates differ across jurisdictions.
Across 14.9 Census sq mi, Diamond Bar logged 64 property and 2.7 violent offenses per square mile in 2024.
Diamond Bar's 2024 book concentrates in larceny-theft (54% of 992 offenses; mix index 4,156).
Violent offenses are only 4% of the municipal total - a property-led book.
Diamond Bar offense mix (2024)
Density uses Census Gazetteer land area (14.9 sq mi); mix index is HHI x 10,000 on the offense-type shares above. Distinct from the per-100K rates in the hero.
| Offense | Count | Rate /100K |
|---|---|---|
| Property Crime | 952 | 1862.1 |
| Larceny-Theft | 532 | 1040.6 |
| Burglary | 346 | 676.8 |
| Motor Vehicle Theft | 74 | 144.7 |
| Arson | 3 | 5.9 |
| Violent Crime | 40 | 78.2 |
| Aggravated Assault | 24 | 46.9 |
| Robbery | 11 | 21.5 |
| Rape | 5 | 9.8 |
| Murder | 0 | 0 |
The chart omits 2021 rather than drawing an unsupported zero or partial-coverage dip. The table preserves the year and marks the gap.
Lead series · rose across 4 comparable years · FBI UCR
Secondary series · fell · 2020-2024 · FBI UCR
| Year | Coverage | Population | Violent Rate | Property Rate |
|---|---|---|---|---|
| 2020 | Comparable | 55,735 | 111.2 | 1430 |
| 2021 | Insufficient reporting | 54,813 | - | - |
| 2022 | Comparable | 52,713 | 174.5 | 1843.9 |
| 2023 | Comparable | 51,863 | 135 | 1933.9 |
| 2024 | Comparable | 51,126 | 78.2 | 1862.1 |
Diamond Bar Police Department filed the 2024 UCR row behind Diamond Bar's 992 reported offenses (4-year span 2020-2024, with internal gaps).
This agency reports via the traditional Summary Reporting System (SRS): aggregate monthly offense counts rather than incident-level detail.
Crime rates read differently at different scales, so these are the California cities closest to Diamond Bar in population. Their populations run from 49,948 to 52,205, against 51,126 here. Or use our side-by-side compare tool to benchmark two cities directly.
Diamond Bar sits at 78.2/100K violent (grade A); the California cities below are the nearest matches after size peers are removed.
Diamond Bar at 78.2/100K violent and 1,862.1/100K property - matched below outside California (≥10k pop, latest UCR vintage; not the in-state lists above).
78.2/100K here; nearest out-of-state matches.
1,862.1/100K here; violent-rate peers above excluded.
Out-of-state cities whose violent rate moved a similar share from 2023→2024 (-42.1% here); level-based peers above are excluded.
In 2024, Diamond Bar reported 40 violent crimes and 952 property crimes, for a total of 992 reported offenses.
From 2023 to 2024, Diamond Bar's violent crime rate decreased by 42.1%, and the property crime rate decreased by 3.7%.
The most common crime type in Diamond Bar is larceny-theft, accounting for 53.6% of all reported crimes (532 incidents in 2024).
Large-city read: Diamond Bar's rates come from the FBI Uniform Crime Reporting (UCR) Program, CIUS Table 8, vintage 2024.
Incomplete reporters stay out of rate rankings. Cross-check population with Census ACS; state UCR programs for statewide context. Primary verify links: FBI.gov UCR, Census QuickFacts.
Disclaimer (large city): informational crime rates only - not legal, insurance, or personal-safety advice. Source: FBI UCR. Ask a qualified professional before acting.
Large-city rate methodology for how Diamond Bar's large city row is sourced and ranked.
Source: FBI Uniform Crime Reporting (UCR) Program CIUS Table 8 municipal crime rates · 2024 Diamond Bar, CA rates use the reporting-year population on the municipal row.
Bulk download: city crime dataset (CSV/JSON)
Every figure on PlainCrime is rendered directly from FBI Uniform Crime Reporting (UCR) source data, no number is typed in by an editor. Diamond Bar is scored here as a large city UCR reporter (51,126 on the row). See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.