Report to the Co-Chairman, Caucus on

International Narcotics Control,

U.S. Senate

United States General Accounting Office

GAO

March 2002 DRUG CONTROL

DEA Could Improve

Its Heroin Signature

and Domestic Monitor

Programs' Geographic

Source Data

GAO-02-416
Page i GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

Letter 1

Results in Brief 2

Background 4

Scope and Methodology 7

Purpose of the HSP and DMP Is To Produce Data That Detect

Trends in Heroin Sources 8

Federal Law Enforcement Used the HSP and DMP Data for

Intelligence Purposes and Management 9

Quantity of Heroin Seized at Ports-of-Entry by Customs but not

Sent to DEA for Testing May Be Sufficient To Make a Difference

in Results Reported by DEA 11

The HSP and DMP Data Could Be Improved 13

Conclusions 15

Recommendations 16

Agency Comments 17

Appendix I Heroin Signature Program 20

HSP Methodology 20

HSP Limitations 21

HSP Opportunities for Improvements 22

Appendix II Domestic Monitor Program 26

DMP Limitations 26

DMP Opportunities for Improvements 28

Appendix III Comments from the Drug Enforcement

Administration 29

Tables

Table 1: Source and Selection for HSP Heroin 6

Table 2: U.S. Customs Service Heroin Seizures (by line items) 12

Table 3: U.S. Customs Service Heroin Seizures Weighing at Least

100 grams, Fiscal Years 1998-2000 (by line items) 13

Table 4: Geographic Source and Percentage of Seized Heroin,

Calendar Year 1999 21

Table 5: Stratified HSP Sample Design 23

Table 6: By Metropolitan Area, the Number of Exhibits from Each

Geographic Source, Calendar Year 1999 26

Contents
Page ii GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

Figure

Figure 1: DEA Case/Seizure/Exhibit 5

Abbreviations

DAWN Drug Abuse Warning Network

DEA Drug Enforcement Administration

DMP Domestic Monitor Program

FBI Federal Bureau of Investigation

HSP Heroin Signature Program

MOU Memorandum of Understanding

ONDCP Office of National Drug Control Policy

SEACATS Seized Assets and Case Tracking

STRL Special Testing and Research Laboratory

TECS Treasury’s Enforcement Communications System
Page 1 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

March 29, 2002

The Honorable Charles E. Grassley

Co-Chairman, Caucus on International

 Narcotics Control

United States Senate

Dear Senator Grassley:

The Drug Enforcement Administration (DEA) administers two programs,

the Heroin Signature Program (HSP) and the Domestic Monitor Program

(DMP), that serve as indicators for assessing trends in the geographic

source of heroin supplied to the United States. These programs produce

data on the geographic source of heroin through a series of chemical

analyses and are the only programs of their kind in the United States. The

HSP reports the geographic source of heroin seized at ports-of-entry

(primarily by the U.S. Customs Service) and other locations, as well as

wholesale level purity. The DMP reports the geographic source of heroin

purchased undercover in 23 U.S. metropolitan areas, as well as retail level

heroin purity and price. This report does not focus on purity and price.

This report responds to your request that we review how DEA captures

and reports the data for the HSP and DMP and that we provide, if

appropriate, possible alternative approaches for DEA to consider to

improve the HSP and DMP data.1

 Specifically, this report discusses

• the purpose of the HSP and DMP;

• how federal law enforcement uses the data generated by the HSP and

DMP;

• whether the quantity of heroin seized at ports-of-entry by Customs, but

not sent to DEA for testing, is sufficient to make a difference in the results

reported by DEA; and

• whether the HSP and DMP data could be improved.

 1

 GAO’s Office of Special Investigations provided you with information on the two

programs. U.S. General Accounting Office, Review of the Drug Enforcement

Administration’s Heroin Signature and Domestic Monitor Programs, GAO-01-237R,

(Washington, D.C.: 2001).

United States General Accounting Office

Washington, DC 20548
Page 2 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

To address these areas, we met with officials from DEA, Customs, and the

Office of National Drug Control Policy (ONDCP) concerning the purpose

and operations of the HSP and DMP and how federal law enforcement

uses the data generated by the programs. We obtained and analyzed data

from Customs to determine the quantity of heroin that is seized at ports-ofentry by Customs, but not sent to DEA for testing. To determine if

improvements could be made in the HSP and DMP data, we met with DEA

officials and reviewed the methodology used by DEA in its design and

implementation of the programs.

The HSP and DMP produce data for detecting trends in the geographic

source of the heroin that is found in the United States.2

 DEA officials

stressed that the purpose of these data is not to provide overall estimates

about the geographic source of heroin. The HSP data are intended to

provide law enforcement with a “snapshot” of where heroin at the

wholesale level originates, but only for the heroin that is tested; the DMP

data are intended to provide law enforcement with a “snapshot” of where

heroin at the retail level, in certain metropolitan areas, originates, but only

for the heroin that is tested.3

According to DEA officials, federal law enforcement used the data

generated by the HSP and DMP for intelligence purposes and as a

management tool. The data are used to develop intelligence and

investigative reports to inform the DEA and other federal law enforcement

agencies about trends in heroin trafficking. According to DEA, federal law

enforcement also used the HSP and DMP data as a management tool to

make adjustments in enforcement activities. For example, changes in HSP

and DMP data, in conjunction with data from other sources, could

influence the allocation of federal law enforcement resources from one

location to another. DEA cited the emergence of heroin from South

America as an example of how the data are used. In 1991, intelligence

reports indicated that heroin was entering the United States from South

America and that Southwest Asian heroin producers had taught

Colombians their methods of processing opium into heroin. DEA

subsequently identified, through chemical analyses and this other

 2

 As noted, this report does not focus on the purity and price aspects of the programs.

3

 As used in the context of the two programs, “wholesale” represents heroin seizures at

ports-of-entry and seizures and purchases from heroin dealers made elsewhere in the

United States; “retail” represents individual-use heroin purchases.

Results in Brief
Page 3 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

information, that South America was a new supplier of heroin into the

United States.

The quantity of heroin seized at ports-of-entry by Customs but not sent to

DEA for testing may be sufficient to make a difference in the results

reported by DEA. According to DEA officials, all ports-of-entry seizures

forwarded to DEA by Customs are tested by DEA for geographic source.

However, DEA and Customs officials noted that, in accordance with the

Memorandum of Understanding (MOU) between the two agencies,

Customs is not required to send all heroin seizures to DEA. Our analysis of

Customs’ heroin seizure data revealed that, over fiscal years 1998-2000,4

 57

percent of the total weight of heroin seized by Customs was not sent to

DEA.

The HSP and DMP data could be improved. As currently designed and

implemented, there are limitations in the usefulness of the HSP and DMP

data, because they were based on nonrepresentative samples of their

respective populations. While DEA said that it did not intend to produce

any estimates from the HSP and DMP data, our analysis showed that with

some modifications to its methodology, DEA could produce estimates.

These estimates would provide a stronger basis for law enforcement

decision-making. With modifications to the HSP methodology, estimates

could be made about the geographic source of all seized wholesale heroin

that is sent to DEA for testing. With modifications to the DMP

methodology, estimates could be made about the geographic source of

retail level purchases within the metropolitan areas where they are made,

and the estimates could possibly be combined across the 23 metropolitan

areas. Therefore, we are recommending that the Attorney General direct

the Administrator of DEA to (1) ensure that the HSP data are based on a

probability sample so that all HSP exhibits have a known chance of

selection, (2) revise the HSP methodology for reporting testing results to

include procedures to adjust for the probability of exhibits being selected

for the test sample, (3) take action to ensure that DMP purchases are made

according to DEA guidelines, and (4) study the use of alternative data

sources for the total number of retail heroin purchases in an area that

could allow the DMP data to be combined across metropolitan areas.

 4

 We chose these years as they represented the most recent data available at the time of our

analysis.
Page 4 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

We are also recommending that the attorney general and the secretary of

the treasury direct the administrator of DEA and commissioner of

Customs, respectively, to enter into discussions to determine whether

additional seized heroin should be forwarded to DEA by Customs.

We provided DEA, Customs and ONDCP with a draft of this report.

Written comments from DEA are discussed in our Agency Comments

section on pages 17-18.

Each heroin-producing region has a unique production process,5

 or

signature, which generally can be determined through chemical analyses.

In the HSP, seized or purchased substances are forwarded to one of DEA’s

regional laboratories,6

 which confirms whether the substance is heroin. If

the substance is confirmed to be heroin, the laboratory is responsible for

preparing a written report for judicial purposes and, in certain

circumstances, providing a sample to DEA’s Special Testing and Research

Laboratory (STRL) for signature analysis. STRL analyzes the heroin

samples; in most instances, these analyses result in the identification of

the heroin’s geographic source. In the DMP, purchased substances are sent

directly to STRL for analysis.

The heroin that is selected for HSP testing is selected from either “cases”

or “exhibits.” Figure 1 illustrates a possible case that includes multiple

seizures and exhibits.

 5

 The regions are: Southeast Asia, Southwest Asia, South America, and Mexico. The South

American heroin signature was developed in 1993. This heroin is produced mainly in

Colombia.

6

 DEA operates the STRL in addition to its regional laboratories.

Background
Page 5 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

Figure 1: DEA Case/Seizure/Exhibit

Source: GAO’s analysis of DEA information.

As shown in figure 1, a single case can include more than one seizure of

heroin. For example, a single case would include more than one seizure if

agents seized heroin from the same person (the same case), but on

different dates. In turn, a single seizure might include more than one

exhibit, if agents find heroin associated with the same person on the same

date, but at multiple locations. For example, a seizure would include three

exhibits if agents, on the same date, seize heroin from multiple locations

such as the person’s desk, closet, and coat pocket.

DEA initiated the HSP in 1977. Heroin for the HSP is obtained from eight

sources and selected for signature analysis as shown in table 1.

Seizure

#1

9/17/01

Seizure

#2

9/18/01

DEA Case #1906, opened

July 2, 2001

Seizure

#3

9/19/01

Exhibit 1

Coat

Pocket

Exhibit 1

Desk

Exhibit 2

Closet
Page 6 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

Table 1: Source and Selection for HSP Heroin

Source Selected

1. Seizures from passengers, luggage, or cargo on flights that

have originated outside the United States. A sample from each case.

2. Seizures made at nonairport ports-of-entry. A sample from each case.

3. Seizures from letters, packages, or freight shipped by the U.S.

Postal Service or a commercial mail or freight-forwarding

company and that originated outside the continental United

States and were sent to a DEA laboratory for analysis.

A sample from each case.

4. Nonairport seizures in Hawaii, Alaska, and Puerto Rico. A sample from each case.

5. Special requests from DEA. All are to be selected.

6. FBI seizures that have been submitted directly to a DEA

laboratory for analysis. One exhibit from each case.

7. Seizures made by the Washington, D.C., Metropolitan Police

Department.

A random sample of exhibits, determined through the use of

random numbers provided by DEA to its regional laboratories

every 6 months.

8. DEA seizures (includes seizures from flights and mail that

originate inside the United States and Federal Bureau of

Investigation seizures submitted through a DEA field office).

A random sample of exhibits, determined through the use of

random numbers provided by DEA to its regional laboratories

every 6 months.

Source: DEA.

DEA initiated the DMP in its New York Field Division in 1979. The

program has expanded to include 23 metropolitan areas. The DMP was

originally designed to enable DEA to monitor the price and purity of retaillevel heroin sold in the United States; it now also provides for the

purchase of heroin for signature analysis. In the DMP, DEA provides

funding for quarterly purchases by DEA field divisions, that may utilize

cooperating sources to make retail-level purchases of heroin.7

 Ten

purchases are to be made in 22 of the 23 metropolitan areas, each quarter;

in New York City, 20 purchases are to be made in each quarter.8

DEA guidelines provide that a certain number of DMP purchases be made

each quarter, throughout the 3 months of each quarter, and in various

locations in the metropolitan areas. According to the DEA guidelines, it

would seldom be necessary to make more than one purchase in any one

location, per day. The most important requirement is that exhibits should

 7

 According to DEA, a cooperating source is an individual who performs an investigative

activity or provides information regarding drug trafficking, with a reasonable expectation

of confidentiality, under the direction and control of DEA personnel.

8

 The DMP is a collection of undercover retail purchases in the 23 metropolitan areas. The

DEA uses undercover purchases as a substitute for actual retail purchases in these 23

metropolitan areas.
Page 7 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

be purchased from locations within the metropolitan areas that are

dissimilar enough to ensure that they come from different suppliers. Each

purchase should weigh at least 1 gram net, including diluents and

adulterants, to ensure that there is a sufficient amount of pure heroin

available to perform a signature analysis.

According to DEA, the average time necessary to complete the signature

analysis of a heroin sample is about 4 hours, with an associated cost of

about $375 per sample. DEA indicated that the STRL performs signature

analyses of 3,000 heroin samples annually, for a total annual STRL cost of

about $1.13 million. DEA provides its field divisions with a total of

$200,000 annually for the DMP purchases.

DEA prepares annual reports on the HSP and DMP data. The HSP reports

display data on geographic source by net weight on a national basis. The

DMP reports display data on geographic source by the number of exhibits

by metropolitan area.

To determine the purpose of the HSP and DMP and how they operate, we

interviewed officials at DEA’s Office of Intelligence, Forensic Sciences,

and the STRL. We reviewed relevant policies, reports, and other

documentation.

To determine how federal law enforcement uses the data generated by the

programs, we interviewed officials at DEA’s Office of Intelligence and

Office of Forensic Sciences and ONDCP. We also reviewed relevant

documentation of the use made of the data, including documentation of

instances in which changes have been made in federal law enforcement

efforts as a result of the data.

To determine if the heroin seized at ports-of-entry, but not tested by DEA,

is of sufficient quantity to make a difference in the results reported by

DEA, we interviewed officials at DEA’s Office of Intelligence, Office of

Forensic Sciences, and the STRL, as well as Custom’s Smuggling

Investigations Division and Office of Intelligence. We also obtained and

analyzed data from Customs regarding seized heroin in fiscal years 1998-

2000.9

 These data were derived from the Department of the Treasury’s

 9

 DEA maintains signature analysis and HSP and DMP data on a calendar-year basis.

Customs maintains seizure data on a fiscal-year basis.

Scope and

Methodology
Page 8 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

Enforcement Communications System (TECS), Seized Assets and Case

Tracking (SEACATS) subsystem. We did not verify the accuracy of these

data. The data included the date and location of the seizure,10 the total

weight of the seizure (less the weight of any packaging or container), and

the disposition of the heroin. According to Customs, a seizure is recorded

in the system when contraband is discovered and physical custody is

taken. Under Customs’ policy, seizures that involve taking heroin from

more than one place, for example, from an individual’s pocket and from

his suitcase, are counted as one seizure but entered into the system as two

“line items.” We were provided data by line items. Each line item from the

same seizure equates to a DEA exhibit.

To determine if the sample-based HSP and DMP data could be improved,

we interviewed officials at DEA’s Office of Intelligence and Office of

Forensic Sciences. We reviewed sample design and sample selection

methodology and the formulas and methodology used to develop data on

the geographic source of heroin. We obtained and reviewed HSP and DMP

data files for calendar years 1999 and 2000. We reviewed earlier reports,

analyzed current methodology, and how DEA reports and caveats the

figures.

In performing our work, we did not talk with officials from all federal law

enforcement agencies that may make use of the programs’ data. We

performed our work from May 2001 to February 2002, in accordance with

generally accepted government auditing standards. We requested

comments from DEA, Customs, and ONDCP. Comments from DEA are

summarized at the end of this report and contained in appendix III.

According to DEA officials, the HSP and DMP produce data for detecting

trends in the geographic source of heroin supplied to the United States.

Officials stressed that the purpose of these data is not to provide overall

estimates of where all heroin supplied to the United States originates. The

HSP data are intended to provide law enforcement with a “snapshot” of

where heroin at the wholesale level originates. The DMP data are intended

to provide law enforcement with a snapshot of where heroin at the retail

level, in certain metropolitan areas, originates. Officials explained that

they believe that, over time, the snapshots begin to tell a story about what

is happening with drug trafficking patterns. When this happens, officials

 10 Location was defined as airport or other.

Purpose of the HSP

and DMP Is To

Produce Data That

Detect Trends in

Heroin Sources
Page 9 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

can make their decisions, in conjunction with other investigative and

intelligence data.

Officials also stressed that direct comparisons should not be made

between the geographic source data from the HSP and DMP. For example,

the wholesale heroin seized in one market (HSP seizures) may not be

intended for retail-level sale (DMP purchases) in the same market. In

addition, comparisons should not be made between the HSP data and

DMP data because the HSP data reflect law enforcement investigative

priorities and techniques, in terms of where and how seizures are made, as

well as the difficulties associated with the various concealment techniques

used by smugglers. In addition, large quantity seizures of heroin from one

geographic source area may boost that geographic source area’s

representation in the HSP data. This may be especially applicable to

heroin from Southeast and Southwest Asia that has been traditionally

smuggled in large, multikilogram quantities.

The officials also noted that these same factors could influence year-toyear fluctuations in the proportion of heroin from each geographic source

area. For example, law enforcement priorities and smuggler concealment

techniques are reflected in the numerous small-quantity heroin seizures

from Colombian air couriers.

According to DEA officials, the HSP and DMP data are used for

intelligence purposes and as a management tool by federal law

enforcement. Data drawn from a variety of sources, including the HSP and

DMP, are used to develop a comprehensive picture of heroin trafficking in

the United States.11

For example, HSP and DMP data are frequently included in DEA

intelligence and investigative reports to corroborate heroin trafficking

trends in the United States and to inform DEA and other federal law

enforcement agencies about heroin trafficking. In addition, ONDCP

officials noted that the data are used as a confirmation of data from other

sources, such as opium production and cultivation estimates provided by

the Central Intelligence Agency.

 11 Other data sources include opium cultivation/production estimates; investigative

intelligence; other heroin seizure data such as where, when, and from whom heroin was

seized; data from DEA’s System To Retrieve Information from Drug Evidence; and drug

abuse indicator data.

Federal Law

Enforcement Used

the HSP and DMP

Data for Intelligence

Purposes and

Management
Page 10 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

ONDCP officials noted that it uses data from the HSP and DMP for drugflow modeling and that the data,12 which are viewed as one of the better

heroin market indicators, are key components of ONDCP’s data analysis

efforts. ONDCP officials also said that data from the HSP and DMP are

used for such purposes as testimony before the Congress and in ONDCP’s

annual National Drug Control Strategy.

According to DEA, federal law enforcement also uses the HSP and DMP

data as management tools to make adjustments in enforcement activities.

Changes in HSP and DMP data could alert management to changing

trafficking patterns. DEA cited the emergence of heroin from South

America as an example of how the HSP and DMP geographic source data

have been used in law enforcement intelligence and management.

Southeast Asian heroin dominated the market on the East Coast until

1991; Southwest Asian heroin was also readily available. In 1991, a highpurity heroin entered the eastern U.S. market and was initially identified

by DEA as high-purity but atypical Southwest Asian heroin. Intelligence

reports indicated that heroin was entering the United States from South

America. Also, reportedly Southwest Asian heroin producers had taught

Colombians their methods of processing opium into heroin. DEA’s

subsequent determination of a signature unique to South America

confirmed this intelligence and, as a result, South America was identified

as a new supplier of heroin into the United States.

Officials said that the data are also used to monitor the success of various

initiatives. For example, a decrease in the amount of tested heroin that is

found to have originated in a particular geographic source area can be an

indicator that law enforcement initiatives against that particular area have

been successful.

 12 The data are used to develop information on the flow of drugs into the United States.
Page 11 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

According to DEA officials, all ports-of-entry seizures sent to DEA by

Customs are tested by DEA for geographic source. However, for several

reasons, Customs is not required to send all seized heroin to DEA. DEA

and Customs officials noted that Customs is not required to send to DEA

abandoned heroin or heroin that is turned over to state or local officials

for prosecution. “Abandoned heroin” is heroin that cannot be connected to

any individual or defendant. For example, an unmanifested kilogram of

heroin found in an aircraft cargo hold is considered abandoned. Under its

MOU with DEA, Customs is not required to send abandoned heroin to

DEA. Instead, it is to be reported on a Customs Search, Arrest, Seizure

report (CF-151) and turned over to the Customs seized property custodian

for destruction. Also, under the MOU, Customs does not submit for testing

heroin that does not meet local U.S. attorney prosecution guidelines.13

Instead, Customs officials explained that in most instances, this heroin is

to be turned over to state or local officials for prosecution. According to

Customs officials, there are also instances in which the weight of the

seized heroin is so low that it is not turned over to state or local officials

for prosecution. In these instances, it is to be destroyed.

Our analysis of Customs’ heroin seizure data revealed that, for fiscal years

1998-2000, 57 percent of the total weight of the heroin seized by Customs

was not sent to DEA. Data on the number and weight of Customs heroin

seizures,14 including the number and weight of heroin seizures not sent to

DEA for testing, are displayed in table 2.

 13 Each of the 93 U.S. attorneys has discretion as to the minimum threshold weight that will

trigger prosecution in that federal judicial district.

14 Line items from Customs’ database.

Quantity of Heroin

Seized at Ports-ofEntry by Customs but

not Sent to DEA for

Testing May Be

Sufficient To Make a

Difference in Results

Reported by DEA
Page 12 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

Table 2: U.S. Customs Service Heroin Seizures (by line items)

DispositionaNumber of line items Weight of seizuresb

1998 1999 2000 Total 1998 1999 2000 Totalc

Forwarded to DEAd244 353 503 1,100 320.1 425.9 677.1 1,423.1

Not forwarded to DEA 1,078 708 533 2,319 932.5 459.2 496.7 1,888.4

Destroyed 794 380 263 1,437 769.6 326.0 251.2 1,346.8

Turned over to state or local officials or

another federal agency 223 242 164 629 81.9 89.0 136.1 307.1

Abandoned and turned over to state or

local officials or another federal agency 8 37 5 50 3.0 9.8 13.5 26.3

Abandoned and destroyed 15 17 18 50 3.0 .6 2.2 5.8

Abandoned and pending final disposition 0 2 0 2 0 3.8 0 3.8

Not abandoned and pending final

disposition 38 30 83 151 75.0 30.0 93.7 198.6

Total 1,322 1,061 1,036 3,419 1,252.6 885.1 1,173.8 3,311.5

a

Customs seizure disposition categories.

b

Rounded to the nearest tenth of a kilogram.

c

Totals may not equal the individual entries due to rounding.

d

Includes 36 line items, totaling 49.9 kilograms, in which heroin was abandoned but still forwarded to

DEA.

Source: GAO’s analysis of Customs’ data.

According to DEA officials, it is not crucial to test the relatively smaller

seizures. Table 3 displays amounts seized by Customs over a 3-year period.

Of the total number of line items that were not forwarded to DEA, about

72 percent exceeded 100 grams in weight; these line items accounted for

over 99 percent of the total weight of all line items not forwarded to DEA

for testing.
Page 13 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

Table 3: U.S. Customs Service Heroin Seizures Weighing at Least 100 grams, Fiscal Years 1998-2000 (by line items)

Dispositiona

Total number

of line items

Total weight

of line items

Number of line items

weighing 100 grams or

more

Weight of line items

weighing 100 grams or

moreb

Forwarded to DEAc1,100 1,423.1 965 1,418.6

Not forwarded to DEA 2,319 1,888.4 1,675 1,876.0

 Destroyed 1,437 1,346.8 1,193 1,341.3

Turned over to state or local officials or

another federal agency 629 307.1 320 302.0

Abandoned and turned over to state or

local officials or another federal agency 50 26.3 15 25.8

Abandoned and destroyed 50 5.8 12 5.3

Abandoned and pending final disposition 2 3.8 2 3.8

Not abandoned and pending final

disposition

151 198.6 133 198.0

Total 3,419 3,311.5 2,640 3,294.7

Note: Rounded to the nearest tenth of a kilogram.

a

Customs seizure disposition categories.

b

Totals may not equal the individual entries due to rounding.

c

Includes 36 line items, totaling 49.9 kilograms, in which heroin was abandoned but still forwarded to

DEA. The number of line items weighing 100 grams or more was 30, with a total weight of 49.7

kilograms.

Source: GAO’s analysis of Customs’ data.

The HSP and DMP data on the geographic source of heroin could be

improved. The HSP data have limitations; appendix I of this report

describes the current HSP selection methodology, its limitations, and

opportunities for improvements. The DMP data also have limitations;

appendix II describes the current DMP selection methodology, its

limitations, and opportunities for improvements.

According to DEA, it does not intend that the HSP data be used either to

produce estimates as to where all wholesale heroin supplied to the United

States originates or as to where all wholesale heroin seized in the United

States and forwarded to DEA for testing originates.15 Our analysis showed

that the data, with some modifications to DEA’s methodology, could be

 15 For our analysis, seized wholesale heroin is that seized heroin that has been sent to DEA

for signature analysis.

The HSP and DMP

Data Could Be

Improved

HSP Limitations and

Opportunities for

Improvement
Page 14 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

used to produce estimates about the geographic source of all wholesale

heroin seized in the United States and forwarded to DEA for testing. To

make these estimates, the DEA data must be based on a probability

sample.16 The HSP data, however, are not based on a probability sample

because not all exhibits have a known chance of being selected for testing.

Consequently, there is no way to tell how the HSP sample relates to the

universe of all heroin seized in the United States and forwarded to DEA for

testing. Our analysis revealed an additional problem. Even if the HSP data

were based on a probability sample, DEA’s current methodology for

reporting testing results does not include procedures to adjust for the

probability of exhibits being selected for the test sample. Thus, DEA’s

current methodology for reporting HSP testing results would not produce

valid estimates even if a probability sample were used.

With these limitations in mind, opportunities exist for making

improvements that would allow DEA to make valid estimates about the

geographic source of all seized wholesale heroin that is sent to DEA for

testing. These improvements could include modification of sampling

procedures and record keeping to ensure that the HSP data are based on a

probability sample and revision of its methodology for reporting testing

results to include procedures to adjust for the probability of exhibits being

selected for the test sample. (See app. I of this report for detailed

information.)

According to DEA, it does not intend that the DMP data be used to either

produce estimates about retail heroin markets outside the 23 metropolitan

areas covered by the DMP or about the geographic source of all retail level

purchases within the 23 metropolitan areas. Our analysis found that the

DMP data, with some modifications, could produce estimates about the

geographic source of retail level purchases within the 23 metropolitan

areas covered by the DMP, and the DMP estimates could possibly be

combined across the 23 metropolitan areas. These estimates cannot be

made now because of limitations in the DMP sampling and estimation

procedures.

The DMP data are limited for two reasons. First, our analysis showed that

the purchases made by DEA agents were not made in accordance with the

 16 A probability sample means that each exhibit has a known positive chance of being

selected, and this chance could be computed.

DMP Limitations and

Opportunities for

Improvement
Page 15 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

DEA guidelines that indicate that a certain number of purchases should be

made each quarter and that the purchases should be made throughout the

3 months of each quarter. DEA officials told us that they perform periodic

reviews to determine compliance with the guidelines. However, our

analysis found that the required number of purchases was not always

made and that they tended to occur in certain periods of each quarter and

on certain days of the week. Second, the DMP contains no information on

the size of the market in each of the metropolitan areas. For example, City

A could have 10 out of 10,000 purchases tested by the DMP, but in City B

there may be relatively few heroin users and the quarterly DMP sample

could be 10 out of 1,000 purchases. The size of the markets is not known.

As a result, DMP data reflect only DMP purchases.

With these limitations in mind, there are opportunities for making

improvements that would allow DEA to produce estimates about the

geographic source of heroin purchased in the 23 metropolitan areas and to

combine them across the metropolitan areas. These improvements could

include taking action to ensure that DEA agents follow DEA guidelines

when making the DMP purchases and utilizing alternative data sources for

the total number of retail heroin purchases in an area, such as the number

of hospital emergency room admissions related to heroin.17 (See app. II of

this report for detailed information.)

The HSP and DMP data are used for important purposes by federal law

enforcement. For instance, DEA uses the data as an indicator of the

geographic source of heroin found in the United States, to measure the

success of law enforcement initiatives, and to corroborate trends in heroin

trafficking over time. ONDCP uses the data for drug-flow modeling, in

testimony before the Congress, and in its annual National Drug Control

Strategy. We recognize the challenges and difficulties of the HSP and DMP

programs. However, current HSP and DMP data could be providing

misleading information about the geographic source of heroin found in the

United States because of sampling and statistical analysis problems.

Our analysis showed that problems with sampling and statistical analysis

in the HSP might lead to misleading information about the geographic

 17 The Drug Abuse Warning Network (DAWN), administered by the U.S. Department of

Health and Human Services’ Substance Abuse and Mental Health Services Administration,

provides these data.

Conclusions
Page 16 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

source of heroin in the wholesale market. HSP data are derived from a

sample of seized heroin. However, our analysis showed that DEA did not

obtain a large proportion of the heroin seized by Customs, the seized

heroin that was analyzed was not obtained from a random probability

sample, and that the reporting methodology did not include procedures to

adjust for the probability of exhibits being selected for the sample. If a

snapshot of wholesale heroin geographic source is based on HSP data,

then this snapshot may be misleading because accurate information about

seized heroin cannot be developed from the flawed sample.

Our analysis also showed that problems with sampling and statistical

analysis in the DMP might lead to misleading information about the

geographic source of heroin in the retail market also. DMP data are to be

collected from random undercover purchases made in select metropolitan

areas. However, our analysis of DMP data showed that these undercover

purchases were not spread randomly over the year, as provided by DEA

guidelines, but instead were concentrated in certain time periods of the

quarter. Therefore, if the retail market characteristics vary over time or

vary between midweek and weekend, the data could produce results that

would be different from those that might have been obtained had these

guidelines been followed. Furthermore, without knowledge of the size of

the retail markets in the sampled metropolitan areas there are difficulties

in combining DMP results across those metropolitan areas.

The quality/validity of data derived from these two programs could be

improved by more careful sampling, adhering to existing DEA guidelines,

and enhancing data analysis.

To help improve the HSP and DMP data on the geographic source of

heroin, we recommend that the attorney general direct the administrator

of DEA to

• ensure that the HSP data are based on a probability sample so that all HSP

exhibits have a known chance of selection,

• revise the HSP methodology for reporting testing results to include

procedures to adjust for the probability of exhibits being selected for the

test sample,

• take action to ensure that DMP purchases are made according to DEA

guidelines, and

• study the utilization of alternative data sources for an estimate of the total

number of retail heroin purchases in an area that could allow the DMP

data to be combined across metropolitan areas.

Recommendations
Page 17 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

To enhance the usefulness of HSP data, we recommend that the attorney

general and the secretary of the treasury direct the administrator of DEA

and commissioner of Customs, respectively, to enter into discussions to

determine whether additional seized heroin should be forwarded to DEA

by Customs.

We requested comments on a draft of this report from DEA, Customs, and

ONDCP. In its comments, DEA indicated that it strongly disagreed with

two of our recommendations and concurred with the remaining three.

(See app. III.)

DEA disagreed with our recommendations that it (1) ensure the HSP data

are based on a probability sample and (2) revise the HSP methodology for

reporting testing results. DEA said that the HSP should remain a program

whose data are based solely on the results of signature analysis. This

seems to imply that the application of statistical analysis to signature

testing results would yield unscientific data. We disagree. Without the

use of data based on a probability sample, it is impossible to know how to

interpret the HSP data. In addition, DEA seems to imply that we want the

signature of untested exhibits to be imputed based on the results of actual

analyses of tested exhibits. This is incorrect. We recommended the use of

a probability sample and standard weighting procedures that would allow

the estimation of the geographic source of all seized heroin. DEA also said

that it should implement a stratified sample similar to the one we

proposed to ensure that a significant portion of the total weight of heroin

seized by DEA is sampled. However, DEA did not want to use the

stratified sample to produce estimates with the resulting data. We believe

that by implementing a stratified probability sample, DEA could produce

estimates of the seized heroin, which would improve the overall data.

Furthermore, DEA suggested expanding the number of DEA and Customs

exhibits submitted for analysis. However, this method would increase

reliability only if a probability sample were used. Expanding the number

of exhibits submitted without using a probability sample limits the

interpretation of the data to the tested exhibits alone. Finally, DEA said

that the estimation model proposed in our report was simplistic. We

provided this straightforward model only as an example and strongly

endorse any attempt DEA might make to enhance the suggested model.

DEA concurred with the remainder of our recommendations, that it take

action to ensure that DMP purchases are made according to DMP

guidelines; study the utilization of alternative data sources for an estimate

of the total number of retail heroin purchases in an area; and that the

Agency Comments
Page 18 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

attorney general and the secretary of the treasury direct DEA and Customs

to enter into discussions to determine whether additional seized heroin

should be forwarded to DEA by Customs.

DEA concurred with our recommendation that it study the utilization of

alternative data sources for the DMP. DEA also commented that data

sources do not exist that measure either the number of retail heroin

purchases or the prevalence of heroin abuse in a metropolitan area. While

we recognize that these data sources may not exist, we suggested that the

DAWN data could provide a useful surrogate measure; without such a

measure, the DMP data could be misleading.

DEA concurred with our recommendation that DEA and Customs discuss

whether additional seized heroin should be forwarded to DEA. However,

DEA incorrectly characterized our recommendation by saying we

recommended they work to ensure that more seizures are sampled. We

did not make this recommendation. We recommended only that DEA and

Customs discuss whether additional heroin should be forwarded. DEA

officials also provided additional technical comments, which we have

incorporated where appropriate.

Customs and ONDCP said that they had no comments on the draft report.

As agreed with your office, unless you publicly announce its contents

earlier, we plan no further distribution of this report until 30 days from its

issue date. At that time, we will send copies of this report to the cochairman, Senate Caucus on International Narcotics Control; the attorney

general; the secretary of the treasury; the administrator of DEA; the

commissioner of Customs; and the director, Office of National Drug

Control Policy. We will also make copies available to others upon request.

This report will also be available on GAO’s home page at

http://www.gao.gov.

If you or your staff have any questions about this report, please call me or

Weldon McPhail at (202) 512-8777. Other key contributors to this report
Page 19 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

were Doris Page, Mark Ramage, Anthony Patterson, David Alexander, and

Geoffrey Hamilton.

Sincerely yours,

Laurie E. Ekstrand

Director, Justice Issues
Appendix I: Heroin Signature Program

Page 20 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

The Heroin Signature Program (HSP) sample was selected using sampling

procedures for two categories of eligible1

 exhibits. The first category

included exhibits from seizures made by the Drug Enforcement

Administration (DEA) and the Washington D.C., Metropolitan Police

Department. This sample is referred to as the “DEA exhibit sample.” The

second category was comprised of all other exhibits, including those

seizures submitted to DEA by the Federal Bureau of Investigation (FBI),

and those submitted to DEA by the U.S. Customs Service from passengers,

luggage, or cargo on flights that originated outside of the United States.

This sample is referred to as the “POE exhibit sample.” (See table 1 of this

report for additional details on the source and selection of HSP heroin.)

DEA calculated the results of the HSP signature analyses in the following

manner:

• First, the total weight of heroin from sampled exhibits from each

geographic source was computed.2

• Second, the total weight of heroin from sampled exhibits from all

geographic sources was combined.

• Last, the total weight of heroin from each geographic source was divided

by the total weight of heroin for all areas. The result was expressed as a

percentage.

We analyzed calendar year 1999 and 2000 data in our review of the HSP.

Because 1999 was the most recent year for which finalized reports were

available, some analyses are based solely on the 1999 HSP data. According

to DEA, there were no methodological changes from 1999 to 2000.

HSP analyses results for calendar year 1999 are displayed in table 4.

 1

 In order for an exhibit to be eligible for HSP testing, the exhibit must have contained

enough heroin to ensure that a sufficient amount remained after removal of a portion of

the heroin for testing.

2

 Excluded from these sums were heroin amounts associated with sample exhibits for

which a source region could not be determined.

Appendix I: Heroin Signature Program

HSP Methodology
Appendix I: Heroin Signature Program

Page 21 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

Table 4: Geographic Source and Percentage of Seized Heroin, Calendar Year 1999

Geographic source Percentage of seized heroin

South America 60

Mexico 24

Southeast Asia 10

Southwest Asia 6

Source: DEA.

Our analysis of the HSP methodology found that the HSP data, with

modifications, could produce valid estimates about the geographic source

of all wholesale heroin seized in the United States and forwarded to DEA

for testing. These estimates could not currently be made because not all

exhibits had a known chance of being selected for testing; therefore, the

HSP data were not based on a probability sample. In addition, our analysis

revealed that, even if the data were based on a probability sample, DEA’s

current methodology that is used to report testing results would not

produce valid estimates, because it does not include procedures to adjust

for the probability of exhibits being selected for the test sample.

Our analysis showed that, for the following three reasons, not all exhibits

had a known positive chance of being selected for testing.

1. The procedure for selecting the POE exhibit sample resulted in the

selection of heavier exhibits. DEA laboratory personnel were

responsible for identifying POE sample exhibits for testing and,

according to DEA, selected exhibits generally tended to be the heaviest

exhibit from a case. For example, if a POE seizure resulted in 3

exhibits weighing 10 gram, 15 grams, and 50 grams, it was likely that

the 50-gram exhibit was tested. While not conclusive, the DEA exhibit

sample also contained heavier than expected exhibits, suggesting that

the heavier exhibits may generally have been selected for testing.

Although only about 13 percent of the DEA exhibits were sampled in

1999, these sampled exhibits accounted for about 45 percent of the

total weight of seized wholesale heroin sent to DEA for testing.3

 3

 In 1999, DEA laboratories received a total of 2,510 exhibits eligible for the random sample.

For the same time period, 327 exhibits were selected for the random sample, with a total

weight of 151,706 grams.

HSP Limitations

HSP Data Not Based on a

Probability Sample
Appendix I: Heroin Signature Program

Page 22 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

2. Exhibits did not have a known chance of selection because it appears

that DEA did not consistently follow its policy for selecting exhibits,

for either the POE or the DEA exhibit samples.4

 The policy requires

that, except for special request exhibits, no more than one exhibit per

case be chosen. However, based on our review of 1999 and 2000 HSP

data, this policy was apparently not implemented consistently. There

were multiple exhibits for individual cases in the HSP sample for both

1999 and 2000. In 1999, about 9.5 percent and 8.4 percent of the DEA

and the POE sample exhibits, respectively, were from cases that had

multiple exhibits in the sample. For 2000, 10.5 percent and 3.4 percent

of the DEA and the POE sample exhibits, respectively, were from

cases that had multiple exhibits in the sample.

3. Exhibits for the DEA exhibit sample also did not have a known chance

of selection because DEA’s sampling procedures are apparently not

working as intended. Before the start of each 6-month sampling period,

DEA produced a list of random numbers for the DEA exhibit sample. A

separate list of random numbers was sent to each DEA regional

laboratory. The random numbers were to contain approximately 20

percent of the exhibits expected in the sampling period. However, our

analysis showed that the actual percentage of exhibits sampled was 13

percent for 1999 and 8 percent for 2000.5

If DEA developed a probability sample, it would still be unable to produce

valid estimates because its current methodology for reporting HSP testing

results does not include procedures to adjust for the probability of

exhibits being selected for the test sample. In computing estimates using

HSP data, DEA did not take into account that some exhibits had a low

probability of selection and some had a high probability of selection. As a

result, DEA produced only simple tabulations of sample data that could

not be used to produce estimates about the geographic source of all seized

wholesale heroin sent to DEA for testing.

Opportunities exist for making improvements that would allow DEA to

estimate the geographic source of all seized wholesale heroin that is sent

to DEA for testing. These improvements could include (1) modification of

sampling procedures and record keeping to ensure that the HSP data are

 4

 DEA did not provide FBI exhibit data for this analysis.

5

 In 1999, the regional laboratory sample consisted of 327 exhibits out of a total of 2,510; in

2000, the sample consisted of 218 exhibits out of a total of 2,598.

DEA’s Methodology Used

to Report HSP Testing

Results Did Not Include

Procedures to Adjust for

the Probability of Exhibits

Being Selected for the Test

Sample

HSP Opportunities for

Improvements
Appendix I: Heroin Signature Program

Page 23 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

based on a probability sample and (2) revision of its methodology for

reporting testing results to include procedures to adjust for the probability

of exhibits being selected for the test sample. If these improvements were

made, it would also be possible to produce confidence intervals for

estimates.6

HSP sampling procedures could be improved to ensure that all exhibits

have a known chance of selection. For example, DEA could use a

stratified sample in which exhibits are divided into different strata, or

categories, and sample selections are made from each stratum. The

heaviest exhibits and the exhibits DEA considers to have special

intelligence importance could all be selected,7

 and a portion of the

remaining exhibits could also be chosen. Table 5 shows this alternative

sample design.

Table 5: Stratified HSP Sample Design

Stratum

number Description of exhibits

Chance of

selection

1 POE exhibits weighing at least y grams and those for which

DEA makes a special request. 100

2 DEA exhibits weighing at least x grams and those for which

DEA makes a special request. 100

3 POE exhibits weighing less than y grams and for which DEA

does not make a special request. K

4 DEA exhibits weighing less than x grams and for which DEA

does not make a special request. H

Note: Values for x, y, h, and k could be chosen to achieve the desired sample sizes, and sampling

errors and confidence intervals, and to take into account special requests made by DEA to meet

intelligence needs.

Source: GAO’s analysis.

 6

 A particular probability sample is only one of a large number of samples that might have

been drawn using the same sampling procedure. Estimates derived from the different

samples would differ from each other. Confidence in the precision of a particular sample’s

results is expressed as a “confidence interval.” For example, we may be 95 percent

confident that the true population value is within plus or minus 7 percentage points of a

sample estimate.

7

 If, to meet intelligence needs, DEA continues to make special requests for signature

analysis of certain exhibits (not already included in strata 1 or 2 of table 5), the data for

these special request exhibits should not be included in the final estimates of the

geographic source of seized heroin, because they would already have had a chance of

selection.

Modification of Sampling

Procedures to Ensure That

HSP Data Are Based on a

Probability Sample
Appendix I: Heroin Signature Program

Page 24 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

This suggested design would result in a known chance of selection for all

heroin exhibits. All exhibits in strata 1 and 2 would be selected. Exhibits in

strata 3 and 4 would have a less than 100 percent chance of selection. For

example, if k equals 5, then 5 percent of exhibits in stratum 3 would be

selected. If h equals 20, then 20 percent of exhibits in stratum 4 would be

selected.

DEA should also draw the sample and centrally maintain sufficient

records in such a way that the resulting sample selection could be verified.

For example,

• if exhibits are selected manually, with the use of a list of random numbers,

the exhibits should first be numbered sequentially, before the random

number list is used to identify sample exhibits;

• after identifying the sample exhibits, DEA should ensure that sufficient

information is maintained to identify each exhibit, indicate whether the

exhibit was selected for the sample, and whether it was sent for signature

analysis testing; and

• if an exhibit, that is ineligible for testing due to its low weight, were

selected by the sampling procedure, it should be recorded as “insufficient

for signature analysis.”

Several changes to DEA’s methodology are possible that would include

procedures to adjust for the probability of exhibits being selected for the

test sample. For example, DEA could use statistical weights for the sample

design to produce estimates about the geographic source of all seized

wholesale heroin sent to DEA for testing. These statistical weights would

be determined by calculating a value that is the inverse of an exhibit’s

chance of selection. For example, referring to the example following table

5, all exhibits in stratum 1 would be selected and 5 percent of exhibits in

stratum 3 would be selected. Stratum 1 sample exhibits would get a

weighting factor of 1/1=1 and stratum 3 sample exhibits would get a

weighting factor of 1/.05 = 20.

DEA could also use supplemental data to improve the estimates. DEA

could use data on the total weight of seized heroin sent to DEA for testing,

by regional laboratory. This same quantity could be estimated from the

HSP sample. The ratio of these two quantities could then be computed and

used as a refinement to the statistical weights described above. For

example, if one DEA regional laboratory received a total of 210 kg of

heroin, and the sample estimate of heroin for that regional laboratory was

200 kg, then the final statistical weight for sample data from that regional

laboratory would be the initial statistical weight multiplied by

Revision of Current

Methodology to Include

Procedures to Adjust for

the Probability of Exhibits

Being Selected for the Test

Sample
Appendix I: Heroin Signature Program

Page 25 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

210/200=1.05. Using the weighting factor for stratum 3 (from above), the

final statistical weight for stratum 3 sample exhibits selected from that

laboratory would be 20 x 1.05=21.

Estimates of the percentage of seized heroin by geographic source area

would then be computed as follows:

• Compute the total weighted sum of heroin in grams8 for each of six

categories.9

 The weighted sum would use the final statistical weighting

factors described earlier.10 This would produce six sums, H1, ..., H6;

• Compute the total over all six categories, H = H1 + ... + H6;

• The ratio of each category to the total (converted to percentages) would

then yield estimates of the percentages of seized wholesale heroin, sent to

DEA for testing, by geographic region. For example, the percentage from

geographic region i would be pi = 100(Hi / H).

 8

 DEA’s computations did not account for differences in heroin purity levels. DEA could

take this into account by using the amount of pure heroin, if the total amount of pure

heroin is of interest. If the substance of interest were grams of various mixtures of heroin

and adulterants, then an adjustment for purity would not be necessary. However, if a purity

adjustment were not made, it would be difficult to describe what the estimates

represented.

9

 The four geographic source areas plus “unknown” and “insufficient.” DEA’s current HSP

data tables do not report unknown and insufficient.

10 Statistical weighting is an adjustment to data that takes into account the probabilities of

selection.
Appendix II: Domestic Monitor Program

Page 26 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

DEA produced tables using the Domestic Monitor Program (DMP) data.

For example, one table displayed, by metropolitan area, the number of

exhibits from each geographic source. Table 6 displays this information

for calendar year 1999.

Table 6: By Metropolitan Area, the Number of Exhibits from Each Geographic Source, Calendar Year 1999

Metropolitan area Southeast Asia Southwest Asia Mexico South America

Unknown or

insufficient

Atlanta, Ga. 9 1 1 7 7

Baltimore, Md. 2 0 0 33 4

Boston, Mass. 0 0 0 25 12

Chicago, Il. 6 1 0 14 18

Dallas, Tex. 1 0 29 0 6

Denver, Colo. 0 0 23 0 5

Detroit, Mich. 3 4 0 22 8

El Paso,a Tex. 0 0 6 0 0

Houston, Tex. 0 0 38 3 8

Los Angeles, Cal. 0 0 18 0 7

Miami, Fla. 0 0 4 18 10

Newark, NJ 1 0 0 36 7

New Orleans, La. 0 0 0 14 7

New York, NY 0 0 0 54 4

Orlando, Fla. 0 0 0 15 4

Philadelphia, Pa. 0 1 0 33 5

Phoenix, Ariz. 0 0 38 0 2

San Diego, Cal. 0 0 30 0 3

San Francisco, Cal. 0 0 31 0 3

San Juan, PR 0 0 0 24 6

Seattle, Wash. 0 0 37 0 3

St. Louis, Mo. 0 0 33 0 6

Washington, D.C. 4 1 0 20 4

Total 26 8 288 318 142

a

El Paso was added to the DMP in mid-1999.

Source: DEA.

Our analysis of the DMP methodology found that the DMP data, with

modifications, could (1) produce estimates about the geographic source of

retail heroin purchases in the 23 metropolitan areas covered by the DMP

and (2) possibly be combined across the 23 areas. These estimates could

not currently be made because the DMP data have the following

limitations. First, the purchases were not made by DEA agents in

accordance with the DEA guidelines that provide that a certain number of

purchases be made each quarter and that the purchases be made

Appendix II: Domestic Monitor Program

DMP Limitations
Appendix II: Domestic Monitor Program

Page 27 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

throughout each quarter. Second, DMP data analysis did not take into

account the size of the heroin market in each of the metropolitan areas.

DEA agents did not make the DMP purchases in accordance with the DEA

guidelines that provide that a certain number of purchases be made each

quarter and that the purchases be made throughout each quarter.

A review of the 1999 DMP data showed that the DEA guidelines, that

provide that 10 purchases be made in each quarter (20 in New York City)

and that the DMP purchases be spread over the quarter, were not

consistently met. For example, in the first quarter there were less than 5

purchases made in 3 of the metropolitan areas. Our analysis also showed

that a disproportionate number of DMP purchases occurred in a certain

month of a quarter, and on certain days of the week. If the purchases were

spread randomly throughout each quarter, approximately a third of the

purchases would be expected each month, and approximately one seventh

of the purchases would be expected each day of the week. However,

based on our analysis of the DMP data, the purchase dates were not

random by day of the week or by month of quarter.

As a result, it is unlikely that the DMP data for 1999 were derived from a

sample in which the days in each quarter selected for purchases were

chosen with a known, equal probability of selection.1

 In addition, assuming

that the characteristics of retail heroin might change over time, biases may

have been introduced due to oversampling in certain time periods within

the quarter. For example, if the geographic source of heroin supplied to

one location changed between the beginning and the end of a quarter,

making most of the purchases during one part of the quarter would not

reflect the geographic source of the heroin over the entire quarter.

The total number of retail sales in each metropolitan area in each quarter

is not known. As a result, it is difficult to appropriately combine DMP data

across metropolitan areas. For example, in one metropolitan area (City A)

there may be 1,000 retail sales in a quarter, but in another area (City B)

there may be 5,000 retail sales in a quarter. So, for City A, DMP would

sample and analyze 10 purchases representing 1,000 sales, but for City B,

the 10 purchases would represent 5,000 sales. Without knowing how many

 1

 Similar patterns were found in the calendar year 2000 data.

DMP Purchases Are Not

Made in Accordance with

DEA Guidelines

DEA Does Not Take into

Consideration the Size of

the Heroin Markets
Appendix II: Domestic Monitor Program

Page 28 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

purchases are represented by the DMP purchases, the data should not be

combined across metropolitan areas.

Opportunities exist for making improvements that would allow DEA to

estimate the geographic source of heroin purchases in the 23 metropolitan

areas and possibly to combine them across the areas. These improvements

could include ensuring that DEA agents follow guidelines when making

the purchases and using alternative data sources for the total number of

retail heroin purchases in an area.

DEA could take actions to ensure compliance with its own guidelines. For

example, a list of randomly chosen dates on which purchases are to be

made each quarter could be sent to each metropolitan area. Additionally,

actual purchase dates in each metropolitan area could be more closely

monitored, to ensure that purchases are made according to scheduled

dates.

To calculate the chance of selecting any one purchase, the total number of

retail heroin sales per quarter for each metropolitan area is needed. It is

unlikely that this number would ever be known. However, DEA could

study using alternative data sources as a substitute for the total number of

retail heroin sales. For example, the Drug Abuse Warning Network

(DAWN) collects information on hospital emergency room admissions that

are drug abuse related. If the number of heroin purchases in a

metropolitan area is proportional to emergency room mentions for heroinrelated admissions, then DAWN could provide information on the relative

number of heroin purchases by metropolitan area.

DMP Opportunities

for Improvements

Ensure that DEA Agents

Follow Guidelines When

Making DMP Purchases

DEA Should Study the Use

of Alternative Data

Sources for the Size of the

Heroin Markets
Appendix III: Comments from the Drug

Enforcement Administration

Page 29 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs

Appendix III: Comments from the Drug

Enforcement Administration
Appendix III: Comments from the Drug

Enforcement Administration

Page 30 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs
Appendix III: Comments from the Drug

Enforcement Administration

Page 31 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs
Appendix III: Comments from the Drug

Enforcement Administration

Page 32 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs
Appendix III: Comments from the Drug

Enforcement Administration

Page 33 GAO-02-416 DEA's Heroin Signature and Domestic Monitor Programs (440048)
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