Law enforcement agencies in the United States collect criminal incident data that they voluntarily submit to their state Uniform Crime Reporting program, which then transmits the data to the Federal Bureau of Investigation (FBI) as part of the National Incident-Based Reporting System (NIBRS). NIBRS is the national standard for crime data reporting, and it is used to determine crime rates, identify crime trends, and inform policy decisions. However, NIBRS has been critiqued for data quality issues. Although the FBI conducts NIBRS data quality checks, these checks are limited in scope and do not address all data quality issues. This dissertation uses NIBRS data from Georgia and survey data from Georgia law enforcement agencies to examine whether agencies’ data practices and policies are associated with NIBRS data quality, specifically item nonresponse and timely submission. It also examines how submission delays affect the completeness of monthly violent offense counts. Findings indicated that more frequent data quality assessment practices were not significantly associated with lower item nonresponse. Policies requiring incidents to be entered within a specified timeframe were also not significantly associated with more timely NIBRS submissions. Additionally, offense counts based on data submitted within three months of the incident significantly underestimated the number of offenses eventually submitted for homicide, rape, robbery, and aggravated assault. The adjustment approach used in this dissertation produced three-month offense estimates that more closely approximated the total number of offenses eventually submitted to the FBI. These findings demonstrate that the specific data quality assessment practices and incident entry timeframe policies measured in this dissertation are not, by themselves, associated with lower item nonresponse or more timely submissions. The findings also indicate that recently released FBI data should be interpreted with caution, as delayed submissions can substantially affect the completeness of violent offense counts.