Statistical Analysis Presented by James Dodson Richard Koch Cong Liu Stephanie Nguyen and Lei Yang Questions to address for police commissioner Is Stop and Frisk decreasing the guns or other types of weapons in this period ID: 686997
Download Presentation The PPT/PDF document "Stop , Question and Frisk" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Stop , Question and FriskStatistical Analysis
Presented by James Dodson, Richard Koch, Cong Liu, Stephanie Nguyen, and Lei YangSlide2
Questions to address for police commissioner
Is Stop and Frisk decreasing the guns or other types of weapons in this period?
Is Stop and Frisk decreasing crime in general?
Are officers showing a bias during the Stop and Frisk stops?
Overall, predicting that Stop and Frisk is not successful due to low average proportion of success
Overall, predicting that crime is not decreasing
Overall, predicting that biases are held against Black individuals due to large population of stopsSlide3
Our approach to the issue
Visualization Assignment to guide initial predictions and steer hypothesis testing
JMP for clustering for initial data mining and additional analysis
R Programming to review, clean, and analyze data
Identify and evaluate overall dependent and independent variables in dataset
Convert all variables to binary for logarithmic analysis
Descriptive statistics to evaluate year over year changes
Logistic regression to evaluate efficiencies and biases within years
Stepwise regression to evaluate biases Slide4
What data is considered
Searched
Frisked
Arrested
Summons issued
Contraband found
Weapon found
Reason For Stop
Reason for Frisk
Basis for Search
Force Used
Sex
Race
AgeSlide5
Environmental influences
Segmented years for analysis
2003-2005
: Beginning of stop and frisk2006-2009: Heightened frequency of stops
2010-2011
: Initial controversy over release of taped recordings of police instructions to target black individuals
2012-2013
: Heightened visibility and controversy of stop and frisk activity. Marches and social protests begin to occur
2014-2016 : Oversight and court cases impact the process of stop and friskSlide6
Clustering and general predictions
Race impacts whether or not arrest occurs
Younger individuals more likely to be arrestedSlide7
Summary statistics in R
Program more effective in later years
2013 court ruling heavy impacts results
Average stops are males in mid-late 20sSlide8
Logistic regression in R
Arrest (Dependent) ~ Frisk and Search (Independent)
2014 - 2016: Frisk has inverse relationship with an arrest
Potentially inaccurate frisk procedures
Frisk (Dependent) ~ Age, Sex, and Race (Independent)
2006 - 2009: Black as race has inverse relationship with frisk
Police target individuals based on biases, no outcomes to stops
2014 - 2016: Black as race has low P Value, not impactful to the model
Outside forces cause officers to use less biases in stops
Use of Force (Dependent) ~ Age, Sex, and Race (Independent)
All data: Males have direct relationship with use of force, age has inverse relationship.
2014 - 2016, Black as race has low P Value, not impactful to the model
Outside forces cause officers to use less biases in stops
All Data: Hispanics have direct relationship with use of force, does not changeSlide9
Stepwise Regression
Force Use (Dependent) ~ All stop reasons, Age, Sex, and Race
Outcomes:
Age: removed from all models
Males
: Direct relationship with use of force with most years
2014 - 2016 data was removed as a less impacting variable
Race
: Variety of changes through models of different years2014 - 2016 only race variable kept was inverse relationship with Asians and use of force
2006 - 2011 race of Black and Hispanic have direct relationships with use of forceSlide10
Answers for police commissioner
Is Stop and Frisk decreasing the guns or other types of weapons in this period?
Accuracy in arrests, contraband, and weapons increased greatly at 2014. However, only 21% of stops ended in arrest in 2016.
Is Stop and Frisk decreasing crime in general?
As most stops result in misdemeanor crimes. When contrasted with NYC misdemeanor crimes overall, crime did not decrease higher than years prior to stop and frisk.
Are officers showing a bias during the Stop and Frisk stops?
Officers show bias in early to middle years, but lessen as increased public exposure and court rulings impact proceduresSlide11
Questions? Slide12
Outside Sources
https://www.policeone.com/legal/articles/2774108-Cop-who-made-tapes-accuses-NYPD-of-false-arrest/
http://www.reuters.com/article/us-usa-newyork-march-idUSBRE85G0A920120617
http://www.nytimes.com/2013/08/13/nyregion/stop-and-frisk-practice-violated-rights-judge-rules.html