innovations in violent crime reduction strategies...•police-generated dispatches deploy officers...
TRANSCRIPT
Innovations in Violent Crime Reduction Strategies
IACP Annual MeetingsChicago, Illinois
October 28, 2019
Panelists
• Robin S. Engel, PhD, Professor, University of Cincinnati; Director, IACP/UC Center for Police Research and Policy
• Chief Michael Harrison, Baltimore Police Department
• Deputy Chief Chris Jones, Las Vegas Metro Police Department
• Ronal Serpas, Ph.D., Professor of Practice, Loyola University New Orleans
• Tamara Herold, Ph.D., Associate Professor, University of Nevada, Las Vegas
IACP / UC Center for Police Research and Policy (CPRP)
Our Mission: Bring Science to the Streets
• Provide police agencies with access to cutting-edge research, translated into actionable recommendations
• Conduct and facilitate police research; foster collaborative relationships between researchers and police agencies
o Answer urgent policing issues
o Drive sound policy
• Direct access to the field: Research driven by law enforcement, for law enforcement
IACP/ UC Center for Police Research and Policy
Sponsor: Arnold Ventures (formerly the Laura and John Arnold Foundation)
Translate existing research on topics that impact policy & practice• Use of Force • De-escalation Training• Implicit Bias Training• Arrest Decision Making / Alternatives to Arrest• Violence against Law Enforcement• Domestic Violence• First-line Supervision
Conduct large-scale research studies targeting critical issues• Implicit Bias Training (NYPD)• Gang Violence Reduction Strategies (Las Vegas Metro PD)• Use of Force (Tulsa PD and Cincinnati PD)• De-escalation Training (UCPD and Louisville Metro PD)• Case Closure Rates (Knoxville PD)• Reducing Domestic Violence (Tulsa PD)
Most Effective Evidence-Based Violence Reduction Strategies
1. Hot Spots Deployment
2. Focused Deterrence
3. Place Network Investigations
Jurisdiction segments
Intervention Focus
Deferred/Long-termLagged/IntermediateRapid/Short-term
Hot Spot Policing
Focused Deterrence
Place Network Investigations
Onset & Duration
Crime Impact
Complexity
Place Place
Social networks Crime infrastructure
X
X
X
X
X
Partnerships
Low High
Many
Medium
SeveralFew/None
Las Vegas Metro Hot Spots Strategy
Deployment of saturation patrols to specific locations that generate disproportionate amount of crime• 6 month cluster randomized controlled trial (Nov 2018 – Apr 2019)• Randomized 22 Treatment and 22 Control Street Segments• Treatment = patrol officers deployed (randomly via calls for service)
every day, for 2 hours of total exposure at each hot spot each day (15 minute intervals)• Treatment type also randomized: Stationary w/ lights, or Walk
• Control = business as usual• Treatment-to-control conditions geographically proximate (average 3
street segments apart; none within one block of each other)• Abutting segments used to measure possible immediate
displacement or diffusion of benefits
LVMPD Hot Spots and Control Map
Red=Treatment Blue= Control
Las Vegas Metro Hot Spots Strategy
Fidelity assessment indicates strong implementation consistent with research design
• Police-generated dispatches deploy officers to hot spots, and police action (walk or stationary/lights)
• Cleared calls (or late-responses) collected• Each hot spot designated 2 hours total patrolling per day for 6
months• 1.5 hours observed for 90% of all hot spots• 2 hours observed for 55% of all hot spots
Results (1): Hot Spots Strategy
• Treatment locations compared to controls during intervention period (Nov 2018 – Apr 2019)
o55% reduction in violent criminal offenses
o18% reduction in property criminal offenses
o52% reduction in violent calls for service
o12% reduction in property calls for service
Treatment areas (saturation patrols) = fewer CFS and reported criminal offenses (violence and property) compared to controls
Results (2): Hot Spots Strategy
Treatment effect varied by type of treatment
• Stationary with Lights = greatest impact on reducing violent CFS and violent offenses
• Park and Walk = greatest reductions on reducing property offenses
• No impact on property CFS for either type
Results (3): Hot Spots Strategy
• Treatment areas experienced small reductions, while control areas experienced large increases
• Either: (1) crime was going up (but deployment deterred increase in treatment areas), or (2) crime was displaced from treatment to control areas
• Additional analyses comparing treatment and control areas themselves pre/post intervention found slight displacement
BUT … possibility of displacement of crime to other areas detected
Findings Summary: Hot Spots Strategy
• Reduction was strongest for violence, marginal for property
• Stationary with lights had strongest impact on violence(offenses and CFS)
• Walking patrols had strongest impact on property offenses
• Possible crime displacement did occur; impact was slight
Hot spot deployment had strong effect, reducing CFS and reported crimes (property and violence)
Las Vegas Focused Deterrence Strategy
• Offender meetings with law enforcement, social services, and community support messages in May and Oct 2018
• 518 parolees randomized assigned to:• Offender notification meeting (treatment) or • Receive business as usual (control)
• Classified into 4 risk groups (low, low-moderate, mid-moderate, or high) prior to selection into treatment/control conditions
• Randomized Controlled Trial (RCT) designed to test impact solely of offender notification meetings, not full gang enforcement model
Classification TypePrior
Violent ArrestAffiliated w/ Violent Gang
Group 1: Low Risk
Group 2: Low-Moderate Risk
Group 3: Mid-Moderate Risk
Group 4:High Risk
Las Vegas Focused Deterrence StrategyRisk Classification based on: (1) prior violent arrest history, and (2) affiliation with violent gang
Offender Notification Meetings
• 216 probation/parolees assigned to attend meetings (treatment)
• 302 not assigned (control group)
• 1-2 match for lowest risk group; 1-1 match for other risk groups
• Approximately 75% of those assigned to meeting attended
• Messages delivered at meetings:• Law enforcement deterrent message• Social service and assistance-based message• Community message re: harm, impact, and support
Meetings with ~30 attendees conducted on May 8, May 15, and Oct 4, 2018
Classification TypePrior
Violent ArrestAffiliated w/ Violent Gang
Reduced Re-arrest?
Group 1: Low Risk
Group 2: Low-Moderate Risk
Group 3: Mid-Moderate Risk
Group 4:High Risk
Las Vegas Focused Deterrence Strategy
Risk Classification based on: (1) prior violent arrest history, and (2) affiliation with violent gang
Las Vegas Focused Deterrence Strategy:Findings
Probation/Parolees with no violent arrests but gang affiliated, were less likely to be re-arrested after attending notification meeting compared to others in same risk group who did not attend meeting
• 1 out of 4 in treatment group (attended meeting) were re-arrested
25% failure rate
• 2 out of 4 in control group (did not attend meeting) were re-arrested
50% failure rate
• With RCT design, bivariate relationship is strong – suggestive that non-violent individuals exposed to violent groups can be positively impacted by deterrence/social support messages
Offender notification meetings had positive impact on low-moderate risk group