Marble Rock is a city of 575 in Floyd County, about 20 miles southeast of downtown Mason City · Updated November 2026
How common is violent crime in Marble Rock?
Violent crime is low in Marble Rock: an A+, safer than the neighborhoods where 99% of Americans live. Assaults make up 94% of it, and most of those are simple assaults, which involve no weapon and no serious injury.
A+
Violent crime CrimeGrade™
Safety score 991 of 1,000Less violent crime than nearly all US neighborhoodsi What this means
99% of Americans live in neighborhoods with more violent crime than Marble Rock as a whole, and 1% in neighborhoods with less. The typical US neighborhood has a violent crime safety score of 860, a CrimeGrade™ of A. Marble Rock scores 991.
Crime is concentrated in a small share of places, so most neighborhoods score high on the 0 to 1,000 scale. That is why a score in the 800s can still mean more violent crime than most US neighborhoods.
How to read the map: each area's color compares its violent crime with the people who spend time there, on one national scale, from green for the least to red for the most. Each area gets its own color, so a busy downtown or nightlife strip can show red while the homes around it stay green. The interactive maps load faster on a solid connection. Compare high speed internet in Marble Rock, IA at ISP Reports.
Who this page is for: homeowners and renters in Marble Rock, and anyone thinking about buying or renting a home there.
Business and enterprise customers: this free map shows neighborhood areas. CrimeGrade™ business reports map crime at about 66-meter detail and estimate it for one address and type of business. See business reports
Violent crime rates and types in Marble Rock
CrimeGrade™ estimates Marble Rock has about 5.0 reported violent crimes a year for every 1,000 residents, 63% less than the US as a whole and 53% less than Iowa.
All violent crime
Assaults
Robbery
Reported crimes a year, per 1,000 residents. Violent crime here includes simple assaults, which the FBI's violent crime rate leaves out.
Assault is the most common violent crime in Marble Rock, about 94% of the total.
Each CrimeGrade™ here compares a violent crime with the people who spend time in an area, not only the people who live there. Rates count crimes per 1,000 residents.
Select a crime's name to see its map above. CrimeGrade™ business reports map each crime at about 66-meter detail.
Violent crime in Marble Rock and nearby cities
Marble Rock has more violent crime than 7 of its 10 nearest cities. Cartersville and Dougherty have the least violent crime nearby.
Nearest first, with each place's distance from Marble Rock. Beside each violent crime CrimeGrade™ is its safety score, from 0 to 1,000 (higher is safer).
Compared with cities of similar size and density, Marble Rock is safer than 90% of them.
Counting the pain and suffering of victims, violent crime costs Marble Rock about $460,000 a year, or $805 per resident. The costs that reach a bill, such as medical care, lost work and the justice system, come to about $85,000, or $147 per resident.
Billed cost of violent crime per resident, per year
How the cost breaks down
Pain and suffering are about 82% of that full cost.
Crime
Cost a year
Per resident
Murder
$40,000
$69
Rape
$8,600
$15
Robbery
$570
$1
Assault
$36,000
$62
Total
$85,000
$147
How CrimeGrade™ works
The violent crime CrimeGrade™ covers murder, rape, robbery and assault, from A+ for the least crime to F for the most, on one scale for the whole country.
It weighs each violent crime against the people who spend time in an area, so a busy downtown is graded on its workers and visitors as well as its residents.
The rates on this page count crimes for every 1,000 people who live here, the way police departments report them. Marble Rock is a good example: many people work in, shop in or visit it, so its crime per resident looks worse than its CrimeGrade™ suggests.
Comparisons with US neighborhoods use the Census Bureau's block groups, small areas of about 1,400 residents, and count the people who live in each. The figures count crimes reported to police; many crimes, shoplifting above all, never are. Behind the grades, CrimeGrade™ tested 21,607 factors from 125 data families. For business owners, paid CrimeGrade™ location reports estimate crime at a single address for each type of business.
Where the numbers come from
Crime reports that police departments file with the FBI
State crime records and city crime data, where they are published
Published research on what crime costs victims and communities
These are estimates of reported crime for whole areas, not a record of what happened on any one street. CrimeGrade™ updates them once a year and provides them free and without guarantee. Check local sources before you rely on them for a decision.
