RESEARCH DISCIPLINE
Statistical Analysis for Criminology Research
Consulting for Crime & Justice Studies
Criminology research statistical analysis for police and court records, offender follow-up and victimization surveys, with count and recidivism outcomes modeled as they arise and the results prepared to the standard your journal or agency expects.
No Commitment Required
Strictly Confidential
In-House PhD-Level Statisticians
Fixed Project Fee
Same-Day Response
Statistical Analysis for Criminology Research
Criminology research statistical analysis is the statistical design, analysis and reporting of studies of crime, victimization and the justice system, usually from police, court and corrections records, victimization surveys and neighborhood data. Incident counts are often overdispersed, with many zeros, people sit inside neighborhoods, courts and caseloads, and the same person or address can appear in several records, so a Poisson model that ignores the extra variation, or a model that treats every row as independent, returns standard errors that are too small. OnlineSPSS, a specialist statistical consultancy for academic, clinical and professional research, provides criminal justice data analysis through in-house PhD-level statisticians, who settle the unit of analysis, the exposure and the follow-up window with you before any model is fitted.
WHEN TO ENGAGE
Statistical Support at Different Stages of Criminology Research
Criminologists usually come to us at a recognizable point, from defining the follow-up window to an agency's or reviewer's questions about a count model.
Designing a Justice Study You are planning a study of an intervention, a policing practice or a sentencing question and need the unit of analysis, the follow-up window and the outcome definition set before records are requested.
Analyzing Crime and Case Records Your police, court or corrections extract is ready, and the count or recidivism model, the clustering by place or court and the handling of repeat contacts need to be chosen, run and checked.
Preparing a Manuscript or Agency Report Results are ready to be written up and need rate ratios or hazard ratios with intervals, a plain account of the selection assumptions and the reporting your journal or agency expects.
Revisiting a Count or Recidivism Model A model was run on incident data or a recidivism file, and an advisor, reviewer or agency partner has questioned the zero counts, the follow-up time or the claim that a program reduced reoffending.
RESEARCH CONTEXT
Research Designs and Data We Work With in Criminology Research
Criminology draws on police files, court records and surveys of victims, and each source records a different slice of crime that the analysis has to respect.
01
Police and Incident Records
Calls for service, reported incidents and arrests by place and period, where reporting practices and definitions change over time.
02
Court and Sentencing Files
Cases nested within judges, courthouses or jurisdictions, with charges and prior records, where decisions are made on a selected set of defendants.
03
Recidivism and Reentry Cohorts
People released from prison, jail or supervision and followed for rearrest or reconviction, where recidivism analysis must allow for unequal time at risk.
04
Victimization and Self-Report Surveys
Surveys of victimization and delinquency with complex samples, rare outcomes and reference periods that affect recall.
05
Place-Based and Neighborhood Data
Block groups or street segments with counts of incidents, where nearby places resemble one another and the populations at risk differ.
06
Program and Policy Evaluations
Policing, diversion or treatment programs compared with matched or comparison groups, because random allocation is uncommon in justice settings.
METHODOLOGICAL CONSIDERATIONS
Statistical Issues We Consider in Criminology Research
These checks come first in a crime or justice dataset, because the way events were recorded and counted can change a result more than the choice of model does.
Overdispersion and Excess Zeros Incident counts often vary more, and contain more zeros, than a Poisson model allows, so the distribution is examined and negative binomial or zero-inflated models are compared against a substantive account.
Exposure and Time at Risk Counts are modeled with the population, person-time or opportunity that produced them, and recidivism with the follow-up each person had, because raw totals compare unequal exposure.
Nesting in Places and Institutions People sit inside neighborhoods, courts, prisons or caseloads, so multilevel or cluster-robust methods are used and the level at which a finding applies is stated.
Repeat Victims and Repeat Offenders Arrests, victimizations and calls recur for the same person or address. The analysis tracks who contributes several records and does not count each as an independent case.
Selection and Confounding Observational studies of programs or sentences state the selection assumptions and the unmeasured factors that could explain a difference before any claim that a policy reduced crime is made.
Recorded Crime Versus Crime Police data measure reporting and enforcement as well as offending, so changes in practice or definitions are examined before a trend is read as a change in crime.
STATISTICAL METHODS
Methods Selected for the Research Question and Study Design
Each method family is chosen for the outcome and the data structure of your study, and the line under each title explains why it is used with crime and justice data.
Regression & Predictive Modeling
Counts of incidents or offenses are modeled with an exposure term and the dispersion decides between Poisson and negative binomial, while binary outcomes such as rearrest follow logistic models.
Clinical, Survival & Epidemiological
Time to rearrest is censored when follow-up ends and competes with events such as death, and matching adjusts program comparisons for observed differences only.
Longitudinal & Multilevel Analysis
Offenders within courts and incidents within neighborhoods are modeled with random effects or GEE, and a program started in some places is compared with others over time.
Comparative & Hypothesis Testing
Rates of reoffending or victimization in two groups are compared with chi-square or exact tests only where counts and independence allow, with the difference and its interval.
Bayesian & Computational Methods
Records missing for reasons tied to the offense or to agency practice are handled by imputation under stated assumptions, and resampling gives intervals for awkward statistics.
Multivariate, Scale & Reliability
Self-report delinquency and attitude scales are scored and checked for reliability in your sample, and coders of case files are checked for agreement before their codes are analyzed.
DELIVERABLES
Statistical Outputs Prepared for Your Research
The outputs follow the structure of a crime or justice study, from the review of the record layout to the scripts that regenerate every reported rate.
Data & Study Review The record layout, unit of analysis, follow-up windows, exposure measures and offense codes are reviewed, and the share of zeros and repeat contacts is examined before modeling.
Statistical Analysis Count, time-to-event or multilevel models as agreed, with dispersion, influence and fit diagnostics, and sensitivity analyses for selection and for records that are missing.
Effect Estimates & Uncertainty Incidence rate ratios, hazard ratios or adjusted differences in reoffending with confidence intervals that reflect the clustering, and predicted rates in practical terms.
Tables & Figures Descriptive tables by group or area, model tables, cumulative recidivism curves, trend plots and the case-flow counts that reporting standards ask for.
Statistical Interpretation Findings are worded within what the design supports, associations are not written as program effects without the stated assumptions, and the limits of recorded crime are noted.
Analysis Files SPSS syntax, R scripts, Stata do-files or SAS programs, with offense recodes and exposure variables documented, with every table reproducible from the scripts.
REPORTING
Reporting Criminology Research
The guideline follows the design of the study, and each is applied only where it fits.
Observational analyses of police, court or corrections records follow STROBE where the journal asks for it, with the cohort or cross-sectional version matched to the file. Field experiments, such as randomized policing or diversion trials, report to CONSORT 2025, and evaluations without randomization to TREND. Victimization surveys document response with the AAPOR Standard Definitions and describe weights and design variables. Counts are shown with the denominator that produced them, rate ratios and hazard ratios carry confidence intervals, and the handling of zeros, repeat contacts and missing records is reported from the fitted models themselves, so a reader can see what each estimate rests on. Journal and agency requirements are checked on top.
ILLUSTRATIVE EXAMPLE
How the Analysis May Look in Practice
An illustration of how an evaluation built on incident counts moves from police records to a result that respects the data.
ILLUSTRATIVE EXAMPLE · MUNICIPAL VIOLENCE PREVENTION EVALUATION · UNITED STATES
A city public safety office wanted to know whether a street-outreach program was associated with fewer reported violent incidents in the neighborhoods where it operated than in comparable neighborhoods.
Monthly incident counts per block group had many zeros and more variation than a Poisson model allows, block groups were nested in neighborhoods, and the program began in neighborhoods chosen because of recent violence. Before outcomes were examined, we fixed negative binomial models with the resident population as exposure, a comparison of program and comparison neighborhoods before and after the start, and standard errors clustered by neighborhood. Places chosen for recent violence tend to fall back toward their usual level without any program, so the earlier trend was examined and a sensitivity analysis changed the length of the pre-program window. The result was worded as an association under these assumptions.
Outcome: The office received the program-by-period incidence rate ratio with its 95% confidence interval, the pre-trend check, the dispersion diagnostics, a methods paragraph on the evaluation design and the scripts.
This example does not describe a real client or project. We never share details of actual client work, in line with the confidentiality we promise every researcher. This illustrative example is included to show the type, scope, and standard of work involved in this kind of analysis.
RESEARCHER VOICE
What Researchers Say
Feedback from a criminology researcher on records that did not fit a textbook model, on clustering in the data and on output the wider team could use.
“We contacted OnlineSPSS because our dataset was not a textbook example and we needed someone familiar with Criminology & Criminal Justice. They focused immediately on the clustered structure of the data rather than treating every row as independent, then built the analysis around the actual study design. The final output was concise and easy to use with the wider team.”
HOW WE ASSESS YOUR PROJECT
We Review Your Actual Research
Your assessment is based on a review of your actual research materials and analytical requirements, not a generic project category.
You Submit Your Project Details
Share whatever is available at the current stage, such as the research aim, protocol or proposal, dataset, variable list, manuscript or statistical requirements.
We Review Your Research and Define the Scope
Your statistically trained Research Coordinator reviews the materials to understand the study design, research questions, data structure, analytical requirements and expected deliverables. If clarification is needed, additional documents or information can be requested before the assessment is finalized.
Your Analysis Is Completed and Delivered
Once the scope and fixed project fee are agreed, the in-house statistician completes the work and the Research Coordinator remains the communication point through delivery, with the analysis, deliverables and timeline as agreed.
SOFTWARE
Statistical Software for Criminology Research
Crime and justice analyses are run in the package your department or agency already uses, with syntax or scripts provided where applicable.
Statistical Support Within Your Research OnlineSPSS provides the agreed methodological, analytical, and statistical reporting support. The researcher or research team retains the scientific question, substantive interpretation, conclusions, and overall responsibility for the research.
FREQUENTLY ASKED QUESTIONS
Questions About Statistical Analysis for Criminology Research
Short answers to what criminology researchers ask before sharing a dataset, from count models and follow-up time to repeat victimization, confidentiality and the assessment.
Which statistical methods are used in criminology research?
Criminology research most often uses negative binomial and other count models for incidents, survival and competing-risks models for recidivism, logistic regression for binary outcomes and multilevel models for people within places and courts. In criminology regression analysis, the model follows what was counted and how the records were collected. Our Statistical Methods pages describe each family.
Why is a Poisson model often wrong for crime counts?
A Poisson model assumes the variance equals the mean, and crime counts usually vary much more than that. The standard errors are then too small. We check the dispersion and the share of zeros, compare a negative binomial model, and consider a zero-inflated or hurdle model only where there is a substantive reason to expect two processes behind the zeros.
How do you analyze reoffending when people are followed for different lengths of time?
Reoffending is analyzed as time to the first event, with people still event-free at the end of follow-up treated as censored, or as a count with person-time as the exposure. Where another event such as death prevents reoffending, it is handled as a competing event. The follow-up window is fixed before outcomes are examined.
How do you analyze repeat victimization or repeat offending?
Repeat events for one person or address are correlated, so the person or address, not the single event, sets the structure of the analysis. Depending on the question, the number of events per person or address is modeled with a count model and its exposure, the time between events is modeled with methods for recurrent events, or only the first event is kept. The choice is fixed before outcomes are examined, and the number of people or addresses behind each estimate is reported.
How is confidential case and offender data handled?
Research data and project details are handled confidentially, and project information is not published. An NDA is available where required and can be arranged before sensitive materials are shared. Read more about confidentiality and data security.
What happens when I request an assessment, and how long does it take?
You send your research question, a description of the records and any data or protocol you have. A statistically trained Research Coordinator reviews them and responds the same day, and the analysis, deliverables, timeline and one fixed project fee are confirmed before work begins, so the timeline follows from the agreed scope.
Still have a question? Find more answers in our full FAQ.
NEXT STEP
Discuss Your
Criminology Research With Us
Share your research question, the record layout and the data you have, even if only an extract or a proposal exists. We review how events were recorded and counted and confirm the approach before work begins.
No Commitment Required
Strictly Confidential
Fixed Project Fee
In-House PhD-Level Statisticians
Same-Day Response
Serving Researchers Since 2014