Data Sources and
The information about the federal enforcement of the
criminal laws by the DHS and the Justice Department
on this Web site comes from many sources. This is a
guide to the major agency data sources that were
used. It is organized by Web site area.
DHS at Work
This area draws upon a wide scope of information
sources, including background information about
the agency, its history and evolving
responsibilities, as well as its activities. Key
sources of information were Bureau of Immigration
and Customs Enforcement (ICE) agency reports,
congressional hearings, GAO reports, budget
documents, federal court records, and interviews.
Prior scholarly work on the agency was also
examined. Specific figures reported are drawn
from other areas on this site, sources for which
are discussed below.
National Profile and
Enforcement Trends Over Time
Data on aliens deported, inadmissables, and
voluntary departures under docket control came
from INS internal sources. Historical staffing
information about the DHS was obtained from the
Office of Personnel Management. Data sources on
criminal enforcement are discussed at more length
below in the section on district enforcement.
District Enforcement Annual
The primary source for these figures is the federal
prosecutor database compiled by TRAC from
U.S. Justice Department case management data
systems. DHS internal sources were not used.
In the case of Customs, inquiries to the agency
to review TRAC's findings did not meet with any
response from the Customs Service.
In the case of Immigration, available
data on criminal enforcment actions are quite cursory in nature, and TRAC has
uncovered major questions regarding their reliability and validity.
For example, immigration figures for criminal prosecutions and convictions
resulting from DHS investigations are substantially smaller than counts
based upon federal prosecutor records of referrals received from
the former Immigration and Naturalization Service,
or court records on immigration cases.
Coverage includes all referrals recommending
criminal prosecution recorded as received by
federal prosecutors where either the Immigration and
Naturalization Service or U.S. Customs Service
is recorded by Justice
as the lead investigative agency (see
Data Systems for DHS Lag). All criminal
enforcement figures are based upon number of
individuals (defendants or potential
defendants) involved -- rather than number of
cases. A single referral or case filed in court
may involve more than one individual. Each
defendant involved is separately counted in
Population figures used in computing per
capita rates and ranks are county level annual
estimates from the United States Census Bureau.
DHS staff figures are based upon the number of
individuals on the payroll at the end of the
fiscal year by post-of-duty and were compiled
by TRAC from Office of Personnel Management
sources. Unless otherwise noted, the figures
include only fulltime staff in each