U.S. Department of Justice

Office of Justice Programs

National Institute of Justice

DEPARTMENT OF JUSTICE

OFF ICE OF JUSTICE PROGRAMS

BJA NI J OJJDP BJS OVC

The Kansas City Gun Experiment

by Lawrence W. Sherman, James W. Shaw, and Dennis P. Rogan

R e s e a r c h i n B r i e f

National Institute of Justice

Jeremy Travis, Director January 1995

continued p. 2

risk times.6 This argument suggests the hypothesis that greater enforcement of existing laws against carrying concealed

weapons could reduce gun crime. But this

hypothesis had never been tested until the

Kansas City gun experiment.

The experiment developed out of the first

Federal grant awarded under the Bureau of

Justice Assistance (BJA) “Weed and Seed”

program in 1991. The Kansas City (Missouri) Police Department (KCPD) was

given wide latitude in planning its Weed

and Seed strategy. Shortly after the BJA

Handgun crime is increasing rapidly

throughout the Nation,1

 especially in

inner-city areas where youth homicide

rates have skyrocketed.2 While some

scholars argue that more gun carrying by

law-abiding citizens may be the best deterrent to gun violence,3

 others find little

evidence to support that view4

 but much

more evidence that increases in gun

availability produce increases in gun homicides.5

 Still others argue that it is not

the total number of guns in circulation

that increases gun violence, but the carrying of guns in high-risk places at highIssues and Findings

Discussed in this Brief: An evaluation of a police patrol project to

reduce gun violence, driveby

shootings, and homicides in a patrol beat where the homicide rate

was 20 times higher than the national average.

Key issues: Gun crime is rising

rapidly nationwide, while other

types of crime are falling. The need

for strategies to control gun crime

is critical. If police could get more

guns off the street, would there be

fewer gun crimes? This was the

question posed by the Kansas City

program.

Key findings: The results of the

evaluation indicate that directed

police patrols in gun crime “hot

spots” can reduce gun crimes by

increasing the seizures of illegally

carried guns. Specific findings

include:

● Gun seizures by police in the

target area increased by more than

65 percent, while gun crimes declined in the target area by 49 percent (see exhibit 1).

● Neither gun crimes nor guns

seized changed significantly in a

similar beat several miles away,

where the directed patrol was not

used.

● There was no measurable displacement of gun crimes to patrol

beats surrounding the target area.

Exhibit 1: Firearm Offenses/Guns Seized Per 1,000 Persons

Target Beat

37.0

9.9

18.9

16.8

22.6

23.6

10.4

8.8

Gun Crimes

Gun Crimes

Guns Seized

Guns Seized

Before Patrols

0

10

20

30

40

During Patrols Before Patrols During Patrols

Comparison Beat
2

R e s e a r c h i n B r i e f

sumed that if enough potential gun criminals in the area had their guns seized,

they would be unable to commit gun

crimes—at least for as long as it took

them to acquire a new gun.

Neither of these theories could be directly examined within the limits of the

study. Rather, the evaluation study focused on the basic hypothesis that gun

seizures and gun crime would be inversely related. From the outset, the

project team recognized that confirmation

of the hypothesis would not prove that

more gun seizures result in reduced gun

crime. The design could not eliminate all

competing explanations that could be

suggested for the results. But if an inverse correlation between gun seizures

and gun crime were found, it could suggest the value of further research and development. It could also support a policy

of extending the patrols, regardless of the

exact reason for their effectiveness.

award to the KCPD, the National Institute of Justice (NIJ) awarded the University of Maryland a grant to evaluate the

Kansas City effort. This timing allowed

the police and researchers to collaborate

in planning a focused program with a

strong research design.

This Research in Brief explains the

study’s methodology and key findings,

analyzes the reasons for the findings, and

concludes with a discussion of policy implications.

Study design

The program was based on the theory that

additional patrols would increase gun seizures, which, in turn, would reduce gun

crime. Two possible mechanisms were

suggested: deterrence and incapacitation.

The deterrence theory assumed that if police took guns away, illegal gun carriers

would become less likely to carry them in

the area. The incapacitation theory asIssues and Findings

continued . . .

● Driveby shootings dropped from 7

to 1 in the target area, doubled from

6 to 12 in the comparison area, and

showed no displacement to adjoining beats.

● Homicides showed a statistically

significant reduction in the target

area but not in the comparison area.

● Before and after surveys of citizens

showed that respondents in the target area became less fearful of crime

and more positive about their neighborhood than respondents in the

comparison area.

● An investment of 4,512 police officer-hours was associated with 29

more guns seized and 83 fewer gun

crimes, or 54 patrol hours per gun

crime and more than 2 gun crimes

prevented per gun seized.

● Traffic stops were the most productive method of finding guns, with

an average of 1 gun found in every

28 traffic stops.

● Two-thirds of the persons arrested

for gun carrying in the target area resided outside the area.

● Only gun crimes were affected by

the directed patrols, with no changes

in the number of calls for service or

in the total number of violent or nonviolent crimes reported.

Target audience: Mayors, law enforcement officials, public health officials, policymakers, community

leaders, and researchers.

R e s e a r c h i n B r i e f

Exhibit 2: 1991 Characteristics of Target and Comparison Beats

Characteristic Target Beat (144) Comparison Beat (242)

Population 4,528 8,142

% Female 53% 56%

% Under 25 38% 41%

Median Age 32 31

% Nonwhite 92% 85%

% Age 25+ High School Graduates 53% 73%

Residential Square Blocks 80 150

Population Density Per Mile 7,075 4,308

% Single Family Housing 84% 93%

% Land Parcels Vacant 34% 14%

% Houses Owner-Occupied 63% 71%

Median Years Owned 12 10

Median Parcel Value $14,181 $23,953

1991 Firearms-Related Crimes 183 252

(Rate Per 1,000) 40 31

1991 Shots Fired Incidents 86 120

(Rate Per 1,000) 19 15

1991 Driveby Shootings 24 25

(Rate Per 1,000) 5 3

1991 Homicides 8 11

(Rate Per 1,000) 1.77 1.35
3

R e s e a r c h i n B r i e f

stantial volumes of violent crime, which

provided reliable statistics for assessing

trends over time.

Patrol operations. For 29 weeks, from

July 7, 1992, to January 27, 1993, the

Kansas City Police Department focused

extra patrol attention on gun crime “hot

Since the target area, patrol beat 144,

already selected for the “Weed and

Seed” grant had the second highest

number of driveby shootings of any patrol beat in 1991, the police and academic team designing the experiment

chose the reduction of gun crime as the

principal objective of the program. The

program budget for police overtime and

extra patrol cars was then dedicated

to getting guns off the street as costeffectively as possible.

While the evaluation concentrated primarily on this first phase of the Weed

and Seed grant, additional findings

from the evaluation show what happened when the initial funding of patrols stopped (first half of 1993) and

continuation funding allowed resumption of the patrols (second half of

1993).7

Target area. The target beat is an

80-by-10 block area with a 1991 homicide rate of 177 per 100,000 persons,

or about 20 times the national average.8

 In addition to its 8 homicides in

1991, there were 14 rapes, 72 armed

robberies, 222 aggravated assaults

(142 with firearms), and a total of 349

violent felonies—close to one a day.

Exhibit 2 shows that the beat’s population is almost entirely nonwhite, with

very low property values for the predominantly single-family detached

homes. Home ownership rates are very

high; more than two-thirds of all occupants own their homes.

Because the program was restricted to

one target patrol beat—see exhibit 3—

the planning team selected a beforeafter comparison design. The primary

basis for selecting patrol beat 242 in

the Metro Patrol District was its almost

identical number of driveby shootings9

in 1991; 25 driveby shootings in the

control beat compared to 24 in beat 144.

Exhibit 2 also shows that the comparison beat, beat 242, is similar to the target beat in many ways. The major

difference is that beat 242 has almost

twice the population and three times the

land area, including a park. The comparison beat also has slightly higher

housing prices. Both beats have subExhibit 3: Kansas City, Missouri, Police Reporting Areas

531

232 234

231 233

223

221

222

224

134

132 133

131 141

142

114 123 124 321 322 323

112

122

111 121

312

313

311

NORTH KAN. CITY, MO

INDEPENDENCE, MO

N

RAYTOWN, MO

87TH ST

BLUE PKWY

South Patrol

Division

85TH ST

East Patrol

Division

Central Patrol

Division

BLUE RIDGE CUTOFF

STATE LINE RD

SNI-A-BAR RD

MISSOURI RIVER

342

241

243

333

331

332 343

341

113

213 214

212

211

143

Metro Patrol

Division

242

144

Target Patrol Beat Control Beat PROSPECT AVE

39TH ST
4

R e s e a r c h i n B r i e f

spots”10 in the target area. The hot

spot locations were identified by a

University of Maryland computer

analysis of all gun crimes in the area.

The extra patrol was provided in rotation by officers from Central Patrol in

a pair of two-officer cars working on

overtime under the BJA-funded Weed

and Seed program. Four officers thus

worked 6 hours of overtime each night

from 7 p.m. to 1 a.m., 7 days a week,

for a total of 176 nights, with two officers working an additional 24 nights,

for a total of 200 nights, 4,512 officerhours, and 2,256 patrol car-hours.

They focused exclusively on gun detection through proactive patrol and

did not respond to calls for service.

While no special efforts were made

to limit police activities in the comparison area, beat 242, there were

no funds available for extra patrol

time in that area. Several different

I n early 1992, the success of directed

patrols in Kansas City gun crime hot spots

was preceded by two apparently unsuccessful attempts to detect guns. These programs are described below:

Door-to-door gun patrol. The first attempt was a comprehensive program of

door-to-door visits to all 1,259 residences in

the 80-block target beat 144, informing

residents about a new crackdown on gun

carrying and asking them to call an anonymous gun tips “hotline” if they knew of

anyone carrying a gun illegally. The officers

knocked on 1,410 doors in 173 hours of

regular patrol time from March to May

1992, speaking with an adult at 72 percent

of the occupied residences11—one of the

highest success rates in any door-to-door

policing program.12 Of the 786 adult residents to whom the police explained the

“gun tips” program, 96 percent (756) said

they would be willing to call the hotline,

and many were extremely enthusiastic. Unfortunately, only two calls were received.

The door-to-door gun tip results reveal an

important limitation on the police-citizen

“partnership” concept of community-based

policing. The fact that the officers were

white and the area was predominantly

black may have made a difference. But the

fact that two-thirds of the persons later

found carrying guns in the beat resided outside the area may have been more important.13 Residents of high crime areas may

simply not have all the information police

need to deal with many crime problems.

concealed weapon. These indicators, such

as frequent touching of the waist to ensure that a gun stuffed in a belt will not

fall down a pants leg, helped Gallagher

make more than 1,000 arrests for carrying concealed weapons. But using the

same methods, Gallagher was unable to

spot any gun carriers during several nights

on patrol in the most violent areas of

Kansas City in June 1992.

This difference may reflect the enormous

difference in density between the two cities: New York has 30 times as many

people in about the same amount of

land. Therefore, in New York most people

walk and use public transit; in Kansas

City, most people travel by car. The Kansas City officers trained to use these

methods did report a few cases in which

the techniques led to detection of a concealed weapon, but only 9 percent of

guns were found in pedestrian checks.16

Despite these results in Kansas City, both

gun tips hotlines and body language cues

may still work well in other cities. The social and physical characteristics of cities

vary widely, and these methods may

work better in different kinds of communities. Most important, the Kansas City

experience demonstrates the importance

of trial and error in any city’s efforts to

get guns off the streets. Given the complexity of the problem, it is unrealistic to

expect the first method tried to be an

automatic success.

However, the door-to-door program may have

produced beneficial results. Exhibit 5 (see page

7) shows that the number of gun crimes in the

target beat began to fall sharply in June 1992,

the month after the 10-week program of doorto-door visits was completed. Gun crimes continued to decrease up to and after the start of

the hot spots patrols. The fact that the number

of guns seized in beat 144 declined in the second quarter of 199214 eliminates the high-risk

gun seizure theory as an explanation of the

June decrease in gun crime. The principal remaining explanations are either the deterrent

effect of making all the door-to-door visits

(with word of mouth spreading about a police

crackdown on gun carrying), or simply random

fluctuation that is evident elsewhere in the time

series for the target beat—such as in the August to October 1991 period (see exhibit 5).

Moreover, the second author found a drop in

total serious crimes in the target beat that also

began in June 1992, a finding consistent with

other door-to-door patrol experiments.15 Thus,

even if door-to-door visits failed to increase

gun seizures, they may still have been useful

for preventing gun crime and other serious

crime.

Body language training. A second unsuccessful attempt to detect guns in Kansas City

was a method that had worked well in New

York City. Detective Robert Gallagher (retired)

of the New York City Police Department

trained a group of Central Patrol Division police

officers in the body language “cues” he used

to recognize when someone was carrying a

Trial and Error in Gun Detection
5

R e s e a r c h i n B r i e f

strategies for increasing gun seizures

were attempted in beat 144 (see “Trial

and Error in Gun Detection”), but

Federal funds for extra police patrol

were expended entirely upon the overtime patrols.

Measures used. Because the extra patrol hours were federally funded, separate bookkeeping was required to

document the time. In addition, an

onsite University of Maryland evaluator accompanied the officers on 300

hours of hot spots patrol and coded every shift activity narrative for patrol

time and enforcement in and out of the

area. Property room data on guns

seized, computerized crime reports,

calls for service data, and arrest

records were analyzed for both areas

under the study. No attempt was made

to conduct victimization surveys, although a before and after survey of the

target and comparison beats was conducted to measure citizen perceptions

of the program.17

Data analyses. The data were examined several different ways. The primary analyses compared all 29 weeks

of the phase 1 patrol program (July 7,

1992, through January 25, 1993, when

the phase 1 funding for the special patrols expired) to the 29 weeks preceding phase 1, using difference of means

tests. Other analyses added all of 1991

and 1993. The 1993 data included 6

months with no overtime patrols and

phase 2 overtime patrols for 6 months

in the second half of 1993. These

analyses thus covered six 6-month periods, two of which had the program

and four of which did not. The citizen

survey analysis compared the amount

and direction of before-after differences in attitudes within beats.

Both shorter and longer periods

around the program were also examTraffic Stops and Reasonable Suspicion

any lay people—and even some

police—underestimate police powers to

search for guns. When a police officer can

articulate a reason for believing that a gun

crime may be about to occur, the U.S. Supreme Court has ruled that the officer

may pat down the outside of the

suspect’s clothing to check for guns (Terry

v. Ohio, 392 U.S. 1, 1968). This ruling

does not give police the right to stop cars

or persons in an arbitrary manner. But it

does imply that when police stop people

for other legally sound reasons, they may

find further evidence that justifies proceeding to frisk a suspect and to search

the passenger compartment of the car.18

When one considers that traffic stops are

the leading cause of police murders in the

line of duty, the logic of this policy may be

clearer, as the following true case study

from Indianapolis implies:

An officer stopped a car in a high crime

neighborhood for running a stop sign. As

the officer approached the driver, he saw

the driver reaching into a belt pack. He

then directed the driver to get out of the

car so he could pat down the belt pack.

Feeling hard metal inside, the officer

opened the pack and found a small

revolver.

The evidentiary standard of reasonable

suspicion is necessarily lower than the

standard of probable cause, which is the

level of evidence required to justify an arrest. In the case study, the driver could

not have been arrested for reaching into

his belt pack. But the behavior did provide a basis for articulating why the officer thought the driver might have had a

gun. Only after the gun was actually

found was there sufficient evidence to

make an arrest for carrying a concealed

weapon without a permit. But the

articulable suspicion allowed the officer

to detect the hidden evidence in a lawful

and constitutional manner.

Other methods used in Kansas City included looking into the car for guns in

plain view on the seat or the floor and

looking for body language of pedestrians

for telltale signs of a gun stuffed inside a

suspect’s clothing. Consent searches of

glove compartments or car trunks are

also legal, as long as the consent is truly

voluntary.

M

Search Upon Arrest 

45% (13)

Frisk for Safety 

34% (10)

Plain View 

21% (6)

Phase 1 Patrols

07/07/92–01/25/93

N=29

How Hot Spot Patrols Seized Guns
6

R e s e a r c h i n B r i e f

Exhibit 4: Gun Crimes Before and During Phase 1 by Beat

Before During

Beat 12/17/91–7/6/92 7/7/92–1/25/93 %Change

Target (144) 169 86 -49%*

Comparison (242) 184 192 +4%

Adjoining Target

141 76 57 -25%

142 106 84 -21%

143 39 44 +13%

213 143 158 +10%

214 104 138 +33%

331 143 175 +22%

332 153 160 +5%

All Kansas City 4,359 4,287 -2%

* Statistically significant t value, P < .05. Before and during weekly gun crime means were

tested for significant differences in all areas displayed. Only the target area showed

enough change for it to be unlikely a result of chance or random fluctuation.

ined for overall impact. Autoregressive

moving averages (ARIMA) models

were used to compare gun crime in the

52 weeks before and after the patrols

in both the target and comparison

beats. Standard chi-square tests were

used to compare 1991 versus 1992 differences in gun crimes for all four

quarters, as well as both half-years, in

both target and comparison beats. No

matter how the data were examined,

the results were similar.

The program in action

Patrol activity. Officers reported

spending 3.27 car-hours of the 12 carhours per night actually patrolling the

target area (27 percent), for a total of

1,218 officer-hours of potential gun

detection and visible patrol presence

in the area. The officers thus spent 70

percent of their time processing arrests

and performing other patrol-related

duties, as well as some patrol work

outside the target area.

Despite their limited time in the area,

the officers generated a lot of activity.

Both in and out of target beat 144, the

directed patrols issued 1,090 traffic

citations, conducted 948 car checks

and 532 pedestrian checks, and made

170 State or Federal arrests and 446

city arrests, for an average of 1 police

intervention for every 40 minutes per

patrol car. There is some evidence that

activity levels declined during October

through January, just as street activity

usually does at the onset of colder

weather.19 The average number of car

checks made per day, for example, began at a high of 6.5 in July, and

dropped to a low of 3.2 in November,

but time in the target area, miles

driven, and traffic citations issued did

not change substantially during the

first 6-month period.

The actual techniques the officers used

to find guns varied, from frisks and

searches incident to arrest on other

charges to safety frisks associated with

car stops for traffic violations (see exhibit 3).20 Every arrest for carrying concealed weapons had to be approved for

adequate articulable suspicion with a

supervisory detective’s signature.

Results of increased patrol

Gun seizures. The federally funded hot

spots patrol officers found 29 guns in

addition to the 47 guns seized in the target beat by other police units during

phase 1 (second half of 1992), increasing total guns found in the beat by 65

percent over the previous 6-month period and almost tripling the number of

guns found during car checks. The ratio

of guns seized to directed patrol time in

the target area was 1 gun per 156 hours,

but the ratio to time actually spent in the

area (and not processing arrests) was 1

gun per 84 hours and 1 gun per 28 traffic stops. Overall, there was an increase

from 46 guns seized in beat 144 in the

first half of 1992 to 76 seized in the last

half.

Once the guns were seized, most of

them were then permanently removed

from the streets. Not all of the guns

were carried illegally; about one-fifth

(14) of the total 76 guns seized in the

target area during phase 1, and 4 of

the 29 guns seized by the extra hot

spots patrols were confiscated by police for “safekeeping,” a practice followed by many police agencies when

officers have reason to believe gun violence may otherwise occur. While

guns taken for this reason are usually

returned to their registered owners

upon application at the property room,

the process can take several days to

several weeks to complete. Illegally

carried guns, on the other hand, are

destroyed by Kansas City police and

not returned to circulation.

Gun crime. There were 169 gun

crimes in the target area in the 29

weeks prior to the hot spots patrols,

but only 86 gun crimes in the 29

weeks during the phase 1 patrols—a

49 percent decrease, with 83 fewer

gun crimes (see exhibit 4). This

change was statistically significant in

both a test of differences of means
7

R e s e a r c h i n B r i e f

(t-test) for that period, and in an

ARIMA model covering an even longer

before and after period.21

The comparison beat 242 showed a

slight drop in guns seized, from 85 in

the first half to 72 in the second half of

1992. It also showed a slight increase

in gun crimes, from 184 in the 29

weeks before the program to 192 gun

crimes in the 29 weeks during the program (see exhibit 5). Neither change

was statistically significant.22

In addition, while gun crime dropped in

beat 144, none of the seven contiguous

beats showed any significant change in

gun crime, as exhibit 5 shows for the 29

weeks before and after tests. Both the

Homicides. Homicides were also significantly lower in beat 144 during the

two 6-month program periods than in

other 6-month periods, from 1991

through 1993, while there were no significant differences in homicides across

those periods in comparison beat 242.

Other crimes. Neither total calls for police service, calls about violence, property or disorder crimes, total offense

reports, nor property or violent offenses

showed any effect of the increased patrol. There were no changes in these

measures in either the target or comparison area. The target area hot spots

patrols focused specifically on guns,

and their effects were limited to gun

crimes.

increases and decreases in gun crime

found across the contiguous beats

were small enough to have occurred

by chance. The 52 weeks before and

after special tests (ARIMA models)

showed significant reductions in gun

crimes in beats 141 and 143.

Driveby shootings. Driveby shootings

in beat 144 dropped significantly

during both 6-month periods of hot

spots patrols (second halves of 1992

and 1993) compared to the 6-month

periods without them. The same

analysis showed no differences in the

beats surrounding 144 and an increase in the comparison beat 242.23

Exhibit 5: Total Offenses With Firearms by Month in Target and Comparison Beats

1989

Monthly Firearm Offenses

Hot Spot

Patrols

Pause in

Hot Spot

Patrols

Hot Spot

Patrols

Reinitiated

1 121 121 121 121 12

1990 1991 1992 1993

0

10

20

30

40

50

60

Target Beat Comparison Beat
8

R e s e a r c h i n B r i e f

Community perceptions. Community

surveys before and after the intensive

patrols showed that respondents in the

target area, beat 144, became less

fearful of crime and more satisfied

with their neighborhood than respondents in the comparison beat 242. Target area respondents also perceived

less physical and social disorder after

phase 1. While target beat respondents

were only marginally more likely to

say that the shooting problem had gotten better and no more likely to say

that overall crime problems had improved, they were significantly more

likely than comparison area respondents to say that neighborhood drug

problems had gotten better.

When the experimental period was

over, crimes involving firearms gradually increased again for 5 months in

the first half of 1993, consistent with

the typical police crackdowns pattern.24

When the phase 2 patrols began in the

second half of 1993, gun crimes

dropped again, although not as consistently as in phase 1.

Analysis of the

gun crime reduction

Assuming that there are 100,000 handguns in Kansas City,25 the seizure of 29

handguns may be considered a drop in

the bucket, an implausible reason for

any significant reduction in gun crime

(Exhibit 6 indicates how gun crime was

defined and recorded). But there are at

least three plausible theories for how

the patrols may have caused a reduction in gun crime: high-risk places,

high-risk offenders, and deterrence.

High-risk places. One scholar has argued that most guns are not at immediate risk of being used in crime.26

Guns seized by police in high gun

crime areas at high crime times may

be far more at risk of imminent use in

crimes than the average handgun.

Another researcher estimated that for

each new cohort of 100 guns, 33 uses

of those guns in crime are reported.27

Those uses could be heavily concentrated among the small fraction of

that cohort that are carried in gun

crime hot spots.

Still, criminals may easily replace

guns seized by police. Connecting the

29 guns seized to the 83 gun crimes

prevented may thus require a further

assumption that gun crime is more

likely to be a spontaneous incident of

opportunity than a planned event and

is relatively infrequent in the career

of any criminal. The contrary assumption—that criminals with guns

commit many gun offenses in a 6-

month period in the same small

area—may be harder to defend. Even

if the suspects who lose their guns to

police quickly replace them, the opportune circumstances for the crimes

prevented by the guns being seized

might not recur as quickly.

High-risk offenders. Some gun carriers, of course, may be far more frequent gun users than others. If 10

percent of the 170 State and Federal

arrests by directed patrols captured

high frequency gun users and if the

arrestees spent the next 6 months in

jail on serious charges from outstanding warrants, then the program’s incapacitation of those 17 offenders

alone may have prevented 83 gun

crimes—a not implausible average of

5 gun offenses each or less than 1 per

month.

Deterrence. Deterrence of gun carrying may be an even more plausible

Exhibit 6: Gun Crimes

“Gun crimes” are defined as any offense report in which the use of a gun by an

offender is reported. The data presented in this report include the following offense types reported as gun crimes on one or more occasions in either the target

or comparison area during the year before and after the initiation of the hot spot

patrols (July 7, 1991, to July 6, 1993):

Offense Type Beat 144 Beat 242

(Target Area) (Comparison Area)

Criminal Homicide 10 30

Rape 6 5

Armed Robbery and Attempts 124 222

Aggravated Assault 293 409

Aggravated Assault on Police 3 1

Burglary 0 1

Simple Assault (gun pointed) 1 0

Destruction of Property 18 38

Kidnapping 0 1

Casualty Injury (firearm) 2 4

Suicide and Attempts 1 1

Totals 468 712
9

R e s e a r c h i n B r i e f

cause of reduced gun crime. The 29

extra gun seizures, 1,434 traffic and

pedestrian stops, or the total of 3,186

arrests, traffic citations, and other police encounters, could have specifically deterred potential gun criminals

who encountered police. Visibility of

police encounters in the hot spots may

have also created a general deterrent

effect among those who were not

checked by police. This argument appears plausible enough to conclude

that directed patrols can reduce gun

crime, regardless of the theoretical

rationale.

Conclusion

The most important conclusion from

this evaluation is that police can increase the number of guns seized in

high gun crime areas at relatively

modest cost. Directed patrol around

gun crime hot spots is about three

times more cost-effective than normal

uniformed police activity citywide, on

average, in getting guns off the street.28

The raw numbers of guns seized in

each beat may not be impressively

large, but the impact of even small increases in guns seized in decreasing

the percentage of gun crimes can be

substantial. If a city wants to adopt

this policy in a high gun crime area,

this experiment proves that it can be

successfully implemented.

There is still much more to be learned,

however, about the entire process of

gun detection and seizure by police.

Until recently, it has not been a priority of either police administrators or

researchers to understand or encourage the factors leading to gun seizures. Little is known about differences across police agencies or police

officers in their respective rates of

gun detection, and it is not even

known how many more guns could be

detected if patrol officers generally

were given more direction and training in how to locate guns in the

course of their routine activities.

What is clear from the Kansas City

gun experiment is that a focus on gun

detection, with freedom from answering calls for service, can make regular

beat officers working on overtime very

productive.

Officer safety. A related conclusion

is that gun detection does not require

large tactical operations. Some police

agencies require three to five patrol

cars to be present at gun patrol car

stops in high gun crime areas, primarily for reasons of officer safety. Yet

in the Kansas City experiment, with

20 times the national homicide rate, a

pair of two-officer cars working independently was able to increase gun

seizures by 65 percent. No gun attacks on officers were reported in the

course of these patrols, and no one

was injured. Rather than assigning

three to five cars to one traffic stop,

police agencies could disperse those

cars over a wider area to obtain even

greater numbers of guns seized from

the same investment in police patrols.

Whether that will increase the risk of

officer injury in the long run is impossible to say. But whatever the level of

that risk, the Kansas City officers

were willing to assume it without

hesitation.

Cautions. Now that police know how to

increase gun seizures in target areas,

the key question is whether that policy

will reduce gun crime without total

displacement. The Kansas City evidence suggests that the policy can

reduce gun crime without local displacement. Only repeated tests of the

hypothesis, however, will show

whether the policy can predictably

produce that result. Previous NIJ

research has also reported unreplicated findings,29 only to have replications show more mixed results.30 The

need for replications is a major caution

for interpreting any research results.

Intensified gun patrols also need other

cautions. They could conceivably have

negative effects on police-community

relations or be a waste of time and

money. They could also pose great

risks to officer safety. They could even

provoke more crime by making youths

subjected to traffic stops more defiant

of conventional society.31

All of these hazards are possible but

unknown. The tradeoff is the wellknown risk of gun violence, which is

extremely high in many inner cities

and still rising. Firearm crimes in Indianapolis, for example, have risen by

220 percent since 1988. In October

1994, the Indianapolis Police Department implemented a citywide policy

implied by the Kansas City results in

gun crime hot spots. Whether a

citywide program can succeed in doing

what Kansas City did in a small area is

an important next question for both research and policy.
10

R e s e a r c h i n B r i e f

Notes

1. Rand, Michael, Guns and Crime,

Washington, D.C.: Bureau of Justice

Statistics, 1994.

2. Reiss, Albert J., Jr., and Jeffrey A.

Roth, eds., Understanding and Preventing Violence, Washington, D.C.:

National Academy of Sciences, 1993.

3. Kleck, Gary, Point Blank: Guns and

Violence in America, New York: Aldine

de Gruyter, 1991.

4. Cook, Philip, “The Technology of

Personal Violence,” In M. Tonry, ed.,

Crime and Justice: A Review of Research, Chicago: University Press,

1991.

5. McDowall, David, “Firearm Availability and Homicide Rates in Detroit,

1951–1986,” Social Forces,

(69)(1991):1085–1101.

6. Wilson, James Q., “Just Take Away

Their Guns: Forget Gun Control,” New

York Times, March 20, 1994:46–47.

7. Data on guns seized by beat, however, are only available for the first

phase.

8. Shaw, James W., “Community Policing Against Crime: Violence and

Firearms,” Ph.D. dissertation, Department of Criminal Justice and Criminology, University of Maryland at

College Park, 1994.

9. As defined by the KCPD Perpetrator Information Center, which classifies driveby shootings from an ongoing

review of incident reports and produces monthly statistics by beat that

are employed in all analyses of those

events discussed in this report.

10. Sherman, Lawrence W., Patrick R.

Gartin, and Michael E. Buerger, “Hot

Spots of Predatory Crime: Routine Activities and the Criminology of Place,”

Criminology, (27)(1989):27–55.

11. See Shaw, 240.

12. See Shaw, 239.

13. See Shaw, 260.

14. See Shaw, table 9.

15. See Shaw, figure 14.

16. See Shaw, 107 and 263.

17. See Shaw, chapter 7.

18. See Pennsylvania v. Mimms, 434

U.S. 106 (1977); Michigan v. Long,

436 U.S. 1032 (1983).

19. See Shaw, 243.

20. See Terry v. Ohio in 392 U.S. 1

(1968).

21. There were two reasons for extending the ARIMA model to cover 52

weeks before and 52 weeks after the

phase 1 startup date of July 7, 1992.

One is that ARIMA models generally

require more data points than the 29

actual program weeks for more reliable

estimates and the elimination of such

factors as seasonality. This is true

even though there is no specific minimum requirement. The other reason is

that under police crackdown theory

(see Sherman, 1990), it was predicted

that the effects of the hot spots patrols

would linger as a form of residual deterrence even after cessation.

22. No difference was found either in a

29-week before/after t-test or a 52-

week before/after ARIMA model.

23. KCPD data on driveby shootings in

beats contiguous to the target beat are

not displayed but are available from

the authors upon request.

24. Sherman, Lawrence, “Police

Crackdowns: Initial and Residual Deterrence,” In M. Tonry and N. Morris,

eds., Crime and Justice: A Review of

Research, Chicago: University of Chicago Press, 1990.

25. See Kleck, 18. There are estimates

of at least 65 million handguns in the

United States, with a population of

more than 250 million people. A rough

application of this same ratio to the

Kansas City population of some

400,000 people suggests at least

100,000 handguns in Kansas City.

26. See Wilson, 46–47.

27. See Reiss and Roth, 282.

28. See Shaw, 288.

29. Sherman, Lawrence W., and R.A.

Berk, “The Specific Deterrent Effects

of Arrest for Domestic Assault,”

American Sociological Review,

(49)(1984):261–272.

30. Sherman, Lawrence W., Policing

Domestic Violence: Experiments and

Dilemmas, New York: Free Press,

1992.

31. Sherman, Lawrence W., “Defiance, Deterrence and Irrelevance,”

Journal of Research in Crime and Delinquency, (30)(1993):445–473.
11

R e s e a r c h i n B r i e f

This report was supported in part by grant 91–

DD–CX–KO56 from the National Institute of

Justice to the University of Maryland. Findings

and conclusions of the research reported here

are those of the authors and do not necessarily

reflect the official position or policies of the U.S.

Department of Justice.

Lawrence W. Sherman is Chief

Criminologist of the Indianapolis

Police Department and Professor

of Criminology at the University of

Maryland at College Park. James

W. Shaw is Assistant Professor of

Criminal Justice at the University

of Texas—Pan American in

McAllen, Texas. Dennis P. Rogan

is the East District Criminologist

of the Indianapolis Police Department and an Associate Research

Scientist in Criminology at the University of Maryland.

The authors present this report in

collaboration with the Kansas City,

Missouri, Police Department, with

special thanks to Police Chief Steven

Bishop, Major Dennis Shreve,

Deputy Chief James Nunn, Captain

John Hamilton, Sergeants Tim

Edwards and David Burns, and Judy

Robinette.

NCJ 150855

The National Institute of Justice is a

component of the Office of Justice

Programs, which also includes the Bureau

of Justice Assistance, Bureau of Justice

Statistics, Office of Juvenile Justice and

Delinquency Prevention, and the Office for

Victims of Crime.
12

U.S. Department of JusticeR e s e a r c h i n B r i e f

Office of Justice Programs

National Institute of Justice

Washington, D.C. 20531

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