Volume 1, Issue 2, January 1999 ISSN 1096-4886 http://www.westerncriminology.org/Western_Criminology_Review.htm © 1999, The Western Criminology Review. All Rights Reserved.

Appendix A

The first case study is Monrovia, a city of forty thousand in the foothills northeast of Los Angeles. That might seem to be an unexpected setting for a curfew experiment. Before curfew was adopted, 12-17 year-olds accounted for less than ten percent of Monrovia's Part I crimes cleared by arrest, a rate half that of the nation. However, in 1994, police and school district officials claimed that juvenile truancy, gang, crime, and drug activity were rising (Safe City/Safe Campus Task Force 1995). Only anecdotal evidence was offered for this claim, and statistical evidence contradicted it. Police reports showed dramatic declines of twenty to thirty percent, both in reported crimes and juvenile arrests, during 1993-94 compared to previous years. In the entire ten month 1993-94 school year ending June 30, 1994, only twenty of the city's three thousand 12-17 year-olds had been cited by police for an offense during school hours--about two per month.Then, on October 18, 1994, Monrovia implemented Ordinance No. 94-16, the nation's first daytime curfew. The curfew prohibited the presence of youth in public on school days from 8:30 a.m. to 1:30 p.m. The fine was $127 or twenty-seven hours of community service. From October 1994 to July 1997, seven hundred ninety-one youth were cited under the ordinance.

Police credited the curfew with contributing to a sharp reduction in theft, auto theft, and burglary (Santoro 1998). The curfew was enthusiastically cited as a model by cities nationwide. The press lauded Monrovia as a "small-town success" in "zero tolerance for youth crime" (Ricardi 1997). President Clinton endorsed it during a campaign stop in Monrovia in 1996. This case study examines claims that the curfew caused, or contributed to, the decline in crime in Monrovia.

DATA AND METHOD

Two measures are available from monthly police department tabulations to analyze crime trends: arrests and crimes reported to police. Monrovia's monthly police reports from January 1992 through July 1997 are the basis of analysis (Monrovia Police Department). These sources provide crimes reported to police and arrests by offense and age. The January 1992-September 1994 period provides thirty-three months of pre-curfew data. October 1994, the month the curfew was implemented, is a transition month. The November 1994-July 1997 period provides thirty-three months of post-curfew data. Arrests and crimes reported to police are compared for these periods. Arrest rates are calculated for ages 12-17 (juveniles subject to curfew) and 18-69 (adults) from both census and California Department of Finance population enumerations and intercensal estimates. Crime figures for Monrovia and for neighboring cities also are available from the state Criminal Justice Statistics Center in California Criminal Justice Profiles, Los Angeles County (1990-95 and 1996, 1997 updates).

These two measures have strengths and limitations. Arrest data provide information on the age of arrestees but not on the large majority of crimes that are not cleared by arrest. In addition, vigorous curfew enforcement may affect juvenile arrest numbers due to greater police contacts with youth. The other measure, crimes reported to police, is a better measure of overall crime but it does not provide information on the age of arrestees. Thus, attributing declines in reported crime to the curfew, as police have done, effectively assumes that juveniles commit all crime. This is a dubious assumption, especially in Monrovia. Police figures show that in the twelve month period before the adoption of curfew, October 1993 through September 1994, juveniles accounted for twenty-two percent of the arrests for Part I offenses and only ten percent of the Part I crimes cleared by arrest. So "crime reported to police" in Monrovia includes the "noise" of the ninety percent of adult-perpetrated offenses drowning out the "signal" of the ten percent committed by youths. Police figures indicate, then, that most of these crimes are associated with adult, not juvenile, activities.

However, reported crime figures can be used to make some educated guesses about juvenile offending. If a curfew reduces juvenile crime, we would expect the effects to be strongest on reported crime (a) during the months of September through June when the curfew is enforced, as opposed to July and August when it is not, and (b) for those crimes juveniles are most likely to commit. Curfew should have the biggest impact on those offenses--arson (a rare crime), robbery, motor vehicle theft, burglary, and other felony theft, in that order--that the FBI's (1997) and Monrovia's clearance and arrest data agree juveniles are most likely to commit. Conversely, we would expect relatively little effect of curfew on those crimes juveniles are least likely to commit, such as aggravated assault, murder, and rape (the latter two also are relatively rare crimes). In agreement with FBI clearance data, Monrovia police figures indicate juveniles are five times more likely to commit robbery and four times more likely to commit property crimes than they are to commit aggravated assault and other violent crimes. For example, Monrovia juveniles accounted for one-third of all robbery arrests and twenty-four percent of robberies cleared by arrest, but only five percent of aggravated assault arrests and three percent of assaults cleared by arrest. Thus, we would expect curfew to reduce robberies much more than aggravated assaults.

Both arrest and reported crime data are examined below. In addition, Monrovia's change in reported crimes is compared to that of eleven neighboring cities for the 1990-96 period. These cities show wide variation in curfew enforcement.

RESULTS

Crimes Reported to Police

Police analysis. In a January 1998 deposition related to a lawsuit filed by several parents challenging the curfew (Harrahill v. Santoro 1997), the Monrovia Police Department's Roger Johnson admitted "there was a problem with the figures," the effect of which was to exaggerate the decline in crime initially attributed to the curfew (Johnson 1998). The department revised the figures and submitted the new estimates as an exhibit, entitled "Crime During School Hours." The revised figures, cited in the press by Chief of Police J.J. Santoro, found "a 29 percent reduction in crime during school hours... associated with truancy," including a forty-six percent decrease in auto theft and decreases in vehicle and residential burglaries of thirty-two percent (Santoro 1998).

Johnson stated in his deposition that the revised figures defined "crimes during school hours" as crimes believed to have occurred on weekdays between 5 a.m. and 3 p.m., from September 1 through June 30 of each year from 1993-94 through 1996-97. Johnson said these hours were chosen to include crimes most likely to have occurred during the curfew hours of 8:30 a.m. to 1:30 p.m. All weekdays were included, so that offenses on Christmas, New Year's, and other non-school days when the curfew was not in effect would be included as "crimes committed during school hours," Johnson testified. Further, crimes committed by adults were included in the tabulation. Thus, even though most of the crimes in the tabulation were committed by adults, and many were committed during non-curfew hours, the conclusions drawn from the tabulation appear to treat all as if they were committed by juveniles during school days.

Klein analysis. The city of Monrovia commissioned a RAND Corporation research scientist to examine the figures. Klein (1998) provided a two-page declaration in Harrahill which repeated the finding that "there was a 29 percent reduction in the Part I crime rate" during school hours in the 1996-97 school year (the latest period available) compared to the 1993-94 school year (the last before the curfew took effect)." In contrast, there was only a 22 percent reduction in Part I crimes during non-school hours between these periods," Klein stated. Therefore, he concluded, "these data suggest the program reduced Part I crimes in Monrovia by about 7 percent (i.e., 29 percent - 22 percent = 7 percent)."

Klein also compared the decline in reported Part I crimes in Monrovia (down 37 percent from 1993 to 1996) to that of all of Los Angeles County (down 22 percent) and California (down 18 percent). He concluded that because "the reduction in serious crimes in Monrovia was far greater than it was in the county as a whole or the state," the effect of the curfew on crime is even greater than the seven percent the first analysis attributed to it.

Reanalysis of reported crime. Klein's study of the police tabulation was inadequate to evaluate the effects of Monrovia's curfew because it employed simple cross-sectional (single-year) analysis and not more extensive time-series data, provided no significance tests showing whether Monrovia's crime declines were in excess of normal variance; considered no alternative hypotheses or measures; and relied solely on reported crime to measure juvenile crime even though ninety percent of reported crime consists of adult offenses not affected by the curfew.

However, a more immediate problem is that we are unable to replicate Klein's calculations. Totals for reported Part I crimes during each September 1 through June 30 period are available from the Monrovia Police Department's Monthly Report, and are consistent with those in the annual California Criminal Justice Profiles for Los Angeles County prepared by the state Center for Criminal Justice Statistics. Monrovia police statistics for crimes reported to police, crimes estimated to have occurred during curfew (school) hours, and (by subtraction) crimes estimated to have occurred during non-curfew hours, are shown in Table A-1. All curfew hours occur during school days, and non-curfew hours are divided into those during the school year (evenings, weekends, and holidays) and those in the summer (July and August).

It is not clear how Klein came to the conclusion that "there was only a 22 percent reduction in Part I crimes during non-school hours." Our reanalysis of police figures finds that the decrease in reported Part I crimes in Monrovia is considerably larger in the summer months and during the hours of the school year when the curfew is not in effect. In particular, the decline in property crime (burglaries, thefts, auto thefts, and arson, the crimes most likely to be committed by juveniles) is substantially greater in the non-curfew hours of the school year and in the summer months than during the curfew hours.

Even though, as the police department conceded, the exact times that many crimes occurred is unknown, this point may not be crucial. Curfews, especially if vigorously enforced, may simply displace crime to non-curfew hours such as evenings and weekends. If curfew enforcement displaces some crime to non-curfew hours, we would expect young offenders to redistribute their offending on a short-term time scale (to proximate evenings or weekends) rather than some distant point in time (e.g. summer months). Even if we accept the police department's estimates of crime during school hours, the decline in reported offenses (and especially for those property offenses juveniles are most likely to commit) is substantially greater during hours that juveniles are legally allowed in public than when the curfew is enforced.

		Non-curfew hours*
Year	Curfew hours*	School year	Summer	Total
1993-94	410	1,205	362	1,567
1994-95	391	1,045	296	1,341
1995-96	380	882	279	1,161
1996-97	293	792	206	998
Change 96-97 vs. 93-94	-28.5%	-34.3%	-43.1%	-36.3%

		Non-curfew hours*
Year	Curfew hours*	School year	Summer	Total
1993-94	388	1,028	308	1,336
1994-95	357	869	266	1,135
1995-96	356	748	239	987
1996-97	276	650	183	833
Change
96-97 vs. 93-94	- 28.9%	- 36.8%	- 40.6%	- 37.6%

		Non-curfew hours*
Year	Curfew hours*	School year	Summer	Total
1993-94	22	177	54	231
1994-95	34	176	30	206
1995-96	24	134	40	174
1996-97	17	142	23	165
Change
96-97 vs. 93-94	- 22.7%	- 19.8%	- 57.4%	- 28.6%

*"Curfew hours" includes reported crimes that police estimate occurred during school hours, Monday through Friday, September 1 through June 30. "Non-curfew hours" includes crimes occurring during other hours from September 1 through June 30 (school year) and during the August (before) and the July (after) bracketing each school year (summer), when the curfew is not in effect. "Total" refers to the full year beginning August 1 and ending July 31, from August 1993 through the most recent available, July 1997. Choosing different groupings of months to aggregate does not change the substantive results.

**Property crimes are burglary, felony theft, motor vehicle theft, and arson. Violent crimes are murder, rape, robbery, and aggravated assault. Part I crimes are the sum of property and violent crimes.

Source: Monrovia Police Department, Monthly Report. Crime During School Hours; California Criminal Justice Profiles, Los Angeles County, 1993-96; Klein (1998).


Comparison with neighboring cities. Klein's second comparison, of Monrovia's crime changes compared to Los Angeles County and California as a whole, also provides no statistical tests to rule out random variability. Further, Los Angeles (population 9.4 million) and California (population 32 million) are diverse aggregations of cities and nonurban areas with radically different approaches to curfew enforcement and varied influences on crime trends. A more logical method is to compare Monrovia's crime decline with that of cities of similar size surrounding Monrovia.

Our analysis compares the Monrovia experience with eleven neighboring, northeastern Los Angeles and San Gabriel Valley cities (Arcadia, Azusa, Baldwin Park, Duarte, El Monte, Glendora, Pasadena, Rosemead, San Gabriel, Sierra Madre, and Temple City). These cities range in population from 11,000 to 136,000 in 1995 and display widely varying levels of curfew enforcement. In comparing the post-curfew period (October 1994 through December 1996) with the pre-curfew period (January 1990 through September 1994), Monrovia did experience a larger decline in Part I crimes reported to police than its eleven neighbors.

However, it is unlikely that the curfew caused or contributed to Monrovia's crime decline. To begin with, there was little relative decline in crime. Monrovia's decrease in seven of the eight index crimes (murder, rape, robbery, burglary, motor vehicle theft, theft, and arson) was not significantly different from the decreases experienced in the eleven neighboring cities in the 1990-96 period. The only crime decline that approaches statistical significance (t = 1.90, p < .10) is aggravated assault (down 56 percent, compared to the regional average of 11 percent). However, aggravated assault is unlikely to be affected by a youth curfew since it results mainly from domestic violence and is the least likely to be committed by juveniles. As noted, Monrovia youth account for only five percent of aggravated assault arrests and three percent of clearances. The decrease in aggravated assault appears correlated with the city's decline in domestic assault reports.

Further, the timing of Monrovia's crime decline does not indicate any special effect of curfew enforcement. If the curfew reduced youth crime, we would expect to see (a) a decline in offenses reported to police that coincides with implementation of the curfew, and (b) for that decline to be more pronounced during the school year than during the summer. Reported Part I crimes decline sharply from 1993 to 1994. However, the drop does not coincide with the adoption of the curfew in late October, but rather during the January-September period that preceded it. In fact, the declining rate of Part I crimes reported to police began in August 1993, fourteen months before the curfew was adopted. The twenty percent decline in reported offenses from 1993 to 1994 (before the curfew took effect) was larger than the decline from 1994 to 1995 (seven percent) afterward.

Finally, the declines in index crime were slightly larger for the months of July and August than during the school months for the thirty-three month post-curfew period (November 1994 through July 1997) compared to the thirty-three month prior period (January 1992 through September 1994) (see Table A-1). In the post-curfew July-August period, reported crime fell by thirty-two percent, including declines of fifty-two percent in violent offenses, thirty-two percent in burglaries, and twenty-seven percent in other property offenses. This compares to a crime decline of twenty-nine percent during the school months of September through June, including a decline of thirty-nine percent in violent offenses, twenty-five percent in burglaries, and twenty-eight percent in other property offenses. Thus, the decrease in reported crime was lower during school months, when the curfew was enforced, than during the summer months ,when it was not.

Arrest Data

Before implementation of its curfew in October 1994, Monrovia had a low juvenile crime rate. Each year after adoption of the curfew, the level of non-curfew crime among youth rose to increasingly higher levels. Youth comprised only 7.9 percent of Monrovia's arrests in the 1993-94 school year; in 1994-95, youth comprised 8.2 percent of its non-curfew arrests; in 1995-96, 14.7 percent; and in 1996-97, 15.1 percent.

Of the 791 curfew citations issued through July 1997, 783 (99 percent) occurred during the ten-month school year. If curfew enforcement causes juvenile crime to drop, we would expect the largest declines to occur in the September-June school months ,when the curfew is enforced. Conversely, we would expect youth crime to increase in the summer months when youths are free to be in public without curfew.

The opposite occurred. After adoption of the curfew, the percentage of youth non-curfew crime shifted sharply and consistently away from summer months and rose during the school year (see Tables A-2 and A-3). Adult crime shifted slightly in the other direction.

Time Period	School year (September-June)		Summer (July-August)
	Youth	Adult	Youth	Adult
Before curfew
1/92 to 10/94 (33 months)	470	5,228	99	1,024
After curfew
11/94 to 7/97 (33 months)	783	5,282	105	1,185
Rate change, after/before	+ 53 %	- 3 %	- 12 %	+ 11 %

* Curfew violations not included. Includes violent, property, drug, and other felonies, and misdemeanors. Rate is based on populations age 12-17 (youth) and 18-69 (adult).


Monrovia experienced a fifty-three percent increase in juveniles arrested for non-curfew crimes during the school months when the curfew was enforced. In contrast, during the months of July and August, when the curfew was not enforced, juvenile crime declined by twelve percent. Adult crime showed only modest changes over the same period.

*Includes violent, property, drug, other felonies, and misdemeanors but does not include curfew/loitering arrests. Pre-curfew is January 1992 through September 1994; post-curfew is November 1994 through July 1997.

We would more curfew citations to be associated with less youth crime. However, Monrovia's curfew citation activity, charted on a month-to-month basis and analyzed by a correlation method called "differencing," explained earlier, is significantly and positively correlated with a greater number of juvenile non-curfew offenses (r = .495, p < .01). Taken together, these findings indicate that a higher level of curfew enforcement is associated with more, not less, non-curfew offending among youth.

Curfew enforcement by race/ethnicity. Curfew in Monrovia is associated with a doubling of its minority youth crime rate. Latino, black, and other nonwhite (nearly all Asian-American) youth comprise fifty-five percent of Monrovia's population age 10-17, sixty percent of its non-curfew crime, and sixty-eight percent of its curfew arrests. Compared to white youth, nonwhite youth are 1.9 times more likely to be cited under the curfew than their representation in the population and 1.4 times more likely to be cited for curfew than their contribution to crime would predict. The disparity between curfew citations of white and nonwhite youth is statistically significant when compared to the proportions of non-curfew crime committed by white and nonwhite youth (data not shown;chi-square = 12.55, p < .001).

During the 33-month post-curfew period, more than half of all the offenses involving minority youth were curfew citations, compared to forty percent of the offenses involving white youth. Minority youth curfew citations (549) exceed all other offenses combined among minority youth (539). During the most recent (1996-97) school year, their 266 curfew citations (compared to 221 non-curfew offenses) include fifty-five percent of the total offenses involving minority youth. In effect, then, the curfew has doubled Monrovia's nonwhite youth crime rate.

Some law enforcement officials, including Chief Santoro, have argued that our initial findings are "based on a factually incorrect assumption, namely, that the number of juvenile arrests accurately measures the number of juvenile crimes being committed at any point in time." Rather, he said, the curfew led to "more (police) contacts with students who were discovered to be truant and, on occasion, involved in gang activity and crime," resulting in more arrests (Santoro 1998:3). This is an inconsistent argument, given that law enforcement authorities have argued for several years that the increase in juvenile violent crime arrests is due to an increase in juvenile violent crimes. Then Attorney General Lungren, in particular, claimed that the decline in juvenile arrests associated with more curfew arrests statewide meant that curfews caused juvenile crime to decline (Krikorian 1996). Further, Monrovia Police Department (1994-97) law incident summary report logs do not reflect a coincidence of curfew enforcement and large numbers of non-curfew arrests, as would be expected if more police contact were the cause of the large increase in non-curfew arrests. Finally, and most importantly, our study did examine crimes reported to police as well as arrests, and the conclusions are the same: the periods of greater curfew enforcement do not show more crime declines than the periods when the curfew is not in effect.

CONCLUSION

Analysis of the two measures of crime in Monrovia lead to reasonably consistent conclusions:

• Juvenile arrests for non-curfew crimes rose more rapidly during the months of curfew enforcement than during summer months of non-enforcement.
  
• Crimes reported to police did not decline as much during the times of curfew enforcement as during times of curfew non-enforcement, either for school or summer months.
  
• Both juvenile arrests and crimes reported to police declined dramatically in the year before the imposition of the curfew. In the year after the adoption of curfew, reported crime declined slightly and juvenile arrests rose.
  
• Monrovia did not show significantly greater declines in reported crime compared to its eleven neighboring cities except in the case of aggravated assault, the offense least likely to be committed by juveniles.

It is reasonable to conclude, then, that adoption and enforcement of the curfew did not lead to reductions in crime or juvenile offending.

Monrovia provides a free summer recreation program that is much more comprehensive than found in other communities. This program may have contributed to the low and declining level of both reported crime and of juvenile arrests during July and August. In contrast, the curfew is a negative approach, particularly toward nonwhite youth. No measure of crime examined here indicates that it has contributed to the decline in crime or that it is a useful policy tool.