Arlington Police Department
2017 Traffic Stop Hit & Enforcement Rate Analysis
This report analyzes the hit rate and enforcement outcomes following traffic stop searches conducted by
the Arlington Police Department (APD), from 1/1/2017 through 12/31/2017. The results discussed below
are tabulated from clearance dispositions that officers selected after each traffic stop. The results indicate
hit rates differed slightly across racial/ethnic groups, but that enforcement outcomes were uniform and
consistent across racial/ethnic groups.
Briefly for content perspective, the hit rate is the number of contraband discoveries versus the number of
searches conducted, while enforcement outcomes are the number of arrests and citations linked to those
contraband discoveries. The relevant concept is that an agency’s enforcement rate (outcomes versus
search hits) should be uniform across racial/ethnic categories, thusly demonstrating the equal application
of lawful police authority. The implicit expectation is that an arrest or citation occur upon the discovery
of contraband.
Before continuing, it should be noted that officers’ use of discretion (the lawful choice to enforce or not
to enforce) absolutely impacts an agency’s enforcement rate. Said more bluntly, the more officers choose
not to enforce when finding contraband or other unlawful acts, the lower an agency’s enforcement rate
becomes. The more disparate enforcement rates become across racial/ethnic categories, the more
disconcerting that agency’s use of lawful authority becomes. As previously stated, no such concerns were
found in these data concerning APD’s 2017 traffic stop hit or enforcement rates.
For summary descriptions of the below bulleted items, please refer to the below Tables and Figure. A
more detailed explanation of the bulleted items follows that.
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APD’s overall hit rate was 47.1%; meaning officers found contraband a little less than half of the
time when conducting traffic stop searches
The hit rate for a probable cause search was 49.1% and for a consent search was 22.0%.
APD’s overall traffic stop search enforcement rate was 94.2%; meaning an arrest or citation
occurred for the vast majority of contraband discoveries
The enforcement rate for African-Americans was 95.5%, Hispanics was 94.6%, and Caucasians was
91.1%
African American, Caucasian and Hispanic drivers collectively accounted for 98.3% of all
contraband hits.
African Americans accounted for 53.3% (647), Caucasians accounted for 25.1% (305) and
Hispanics accounted for 19.9% (241) of all contraband hits.