What factors can influence a police officer’s decision to arrest a suspect after field sobriety tests?

The decision of a police officer to arrest a suspect after field sobriety tests is significantly influenced by several key factors, predominantly the suspect's performance on the tests, their behavior during the encounter, and their Blood Alcohol Concentration (BAC) level.

Performance on field sobriety tests provides the officer with observable, objective measures of a person's motor skills, balance, and cognitive functions, which are critical when assessing impairment. Additionally, the suspect's behavior—such as their level of cooperation, their ability to communicate, and any signs of intoxication like slurred speech or erratic movements—also plays a crucial role in the assessment of sobriety. Furthermore, the BAC level offers a concrete measure of alcohol consumption and is often a deciding factor that can dictate the legal thresholds for impairment. In New York, a BAC of 0.08% or higher is considered over the legal limit for driving.

While other factors, such as weather conditions or time of day, may affect a police officer's overall situational awareness, they are not direct indicators of whether a suspect is impaired. Similarly, the type of vehicle or the presence of passengers might impact an officer's perception of the situation but do not serve as legitimate grounds for determining sobriety or impairment directly.