What are we measuring?
The term "violent crime" as used for this measure includes murder and non-negligent manslaughter, rape, robbery and aggravated assault.  These types of crimes are used nation wide for reporting crime statistics because they are serious crimes and are most likely to be reported to police.  Because crime statistics originate primarily with local law enforcement agencies, having a uniform definition helps ensure that numbers are comparable between local jurisdictions within and between states.  More information on the Uniform Crime Reporting (UCR) Program, including detailed definitions, can be found here.
The crime rates shown on this page represent reported crimes.  It is generally recognized that many crimes go unreported to police.  The National Crime Victimization Survey conducted by the Bureau of Justice Statistics showed that only about half (51.3%) of violent crime victimizations were reported to police nationally in 2016.  While victimization statistics are not available at the county level, the national statistics suggest that crime rates are generally much higher than suggested by statistics based on reported crimes.
Why is it important?
Crime affects communities negatively in a number of ways. Violent crime poses a threat to everyone's personal safety, but crime can also undermine the social fabric by generating fear of strangers and discouraging participation in community life. High crime rates can also impose economic costs on residents through decreased home prices, increased insurance rates and damage to personal property. Crime also discourages the establishment of businesses in a community, which in turn imposes additional hardships on residents.
Crime Scene Do Not Cross
How are we doing?
While the county's violent crime rate declined by about 11% between 2010 and 2016, there was a slight increase of 1.4% in the rate of violet crimes between 2015 and 2016.  In comparison, the national violent crime rate increased by 3.4% over the same period.  Among the four categories of violent crime, the county saw the largest increase in the rate of murder and non-negligent homicide, which rose by 15% between 2015 and 2016.  The next highest increase was in rape, which rose about 4%.  Aggravated assault and robbery increase on only about 1% each.

Violent Crime Rate by City
Despite the overall decline in violent crime in the county, tremendous disparities exist geographically.  The graph below compares violent crimes for each of the cities in the county for the years 2015, 2016 and 2017. (Data were not available for the city of Mountain Park or for the city of South Fulton, which incorporated in May 2017.)  College park continued to have the highest rate of violent crime among all Fulton cities but is notable in that its rate has declined dramatically, falling by over 40% between 2015 and 2017.  Overall, the city of Atlanta and the smaller cities to its immediate south experienced the highest violent crime rates while the cities north of Atlanta experienced the lowest.  Johns Creek, for instance, reported twenty-five violent crimes in 2017 while College Park, a much smaller city, reported nearly ten times as many.
It is important to note that the comparison of jurisdictions in terms of crime rate should not be interpreted as a comparison of the effectiveness of local law enforcement.  The different areas of Fulton County vary drastically in terms of household income, poverty level, economic opportunity, educational attainment, age structure, and population stability, all of which can strongly affect crime levels.
A Preliminary Look at 2017 Crime
The FBI had not released 2017 crime statistics for U.S. Cities as of March 2018; however, the City of Atlanta Police Department makes crime incident data publicly available on a regular basis.  Violent crime in Atlanta accounted for over 60% of all violent crime in Fulton County in 2016 and therefore serves as a good predictor of overall crime levels for the county in  2017.  Analysis of crime incident data from the Atlanta Police Department indicates that violent crime overall was down about 14% from 2016 to 2017.  Of the four major categories of violent crime, only rape showed an increase in 2017.  The largest change was in robberies, which showed a 26% decline between 2016 and 2017.
Historic Trend in Violent Crime