Reading a Stop Report: What the Facts Support and What the Conclusion Skips
Officer Reyes stopped a sedan at 2147 after it drifted across the fog line twice. The driver, Ms. Alvarez, produced a license and registration without fumbling. Reyes noted a faint odor of alcohol and asked whether she had been drinking. Alvarez said, "One glass of wine with dinner, around 1900." Her passenger, Mr. Cole, said, "We left the restaurant at 2100." Alvarez agreed to a field sobriety test. She completed the walk-and-turn without stepping off the line, but swayed during the one-leg stand. A preliminary breath test returned 0.068. Reyes's report closes with: "Based on the odor and the sway, the driver was impaired." The report does not mention speech, eye appearance, or whether Alvarez was asked to repeat the test.
1. Sort the account into (a) observations that support an inference of impairment and (b) observations that cut against it. Then name one detail that is genuinely neutral - consistent with both impairment and sobriety - and explain why it is neutral.
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Supports impairment
- Two fog-line crossings within the observed distance.
- Faint odor of alcohol coming from the driver.
- Sway during the one-leg stand.
- Admission of drinking earlier in the evening.
Cuts against impairment
- License and registration produced "without fumbling" - a specific, recorded sign of coordination.
- She completed the walk-and-turn without stepping off the line, i.e., she passed one of the two tests.
- The preliminary reading of 0.068 is below the 0.08 threshold.
Neutral detail: the statement that she had one glass of wine around 1900. It establishes that alcohol was consumed at some point, which is compatible with impairment, and it is equally compatible with sobriety by 2147. By itself it carries no weight either way; it only becomes evidence when paired with quantity, body weight, timing of the last drink, and food intake, none of which the report records.
2. The report concludes: "Based on the odor and the sway, the driver was impaired." Using only what is written, identify what this sentence leaves out and explain how a reviewer should treat the sentence as written.
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The sentence cites two supporting observations and drops everything else in the same account:
- It omits the exculpatory facts - the clean document production, the passed walk-and-turn, and the 0.068 reading.
- It omits the elapsed time between the admitted drink and the test, which is the fact that would make the observations interpretable.
- It converts two observations into a conclusion without explaining the link between them.
A reviewer should therefore treat the sentence as a conclusion, not a finding. It is not false on its face, but it cannot be evaluated, because the reader cannot see the countervailing facts or the reasoning. The defensible version would report each observation separately and reserve the conclusion, or state explicitly why the observations outweighed the passed test and the sub-threshold reading. The gap is a writing problem, and a writing problem in a report becomes a credibility problem later.
3. Is Alvarez's statement that she drank "around 1900" consistent with a 0.068 reading at 2147? State what can and cannot be concluded, and list the information you would need to resolve it.
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What can be said: the two facts are not automatically contradictory, but they sit awkwardly together. 2 hours 47 minutes is a long interval, and a single glass of wine consumed at 1900 would ordinarily be largely eliminated by 2147. A reading of 0.068 at that hour points toward either more alcohol than described, or a drink much closer to the stop, or an unreliable test.
What cannot be said: the account alone cannot establish which of those is true. Elimination depends on body weight, sex, food intake, the size and strength of the pour, and the exact time of the last sip - none of which appear in the report.
Information needed:
- Number of drinks, pour size, and ABV.
- Time of the last drink, not the start of dinner.
- Body weight and whether she ate.
- Whether the 0.068 was a single test or the lower of two readings.
The correct treatment is to flag the tension and seek the missing facts, not to resolve it by assuming the driver understated her drinking.