What is the probability of a suspect being above a .08 BAC with 2 clues from the one leg stand test?

The probability of a suspect being above a .08 BAC based on performance in the one leg stand test is determined through statistical analysis of data from field sobriety tests. The one leg stand test assesses an individual's balance and coordination, which are typically impaired by alcohol consumption.

When two clues are present in the one leg stand test, research and studies indicate that there is a high correlation between those clues and a significant level of impairment, such as reaching or exceeding a .08 BAC threshold. The statistic indicating an 83% probability suggests that individuals demonstrating two clues during this test are very likely to have a BAC at or above the legal limit for driving in many jurisdictions.

This percentage is drawn from empirical data that shows how often performance on such sobriety tests aligns with blood alcohol concentrations measured medically. The specific choice of 83% reflects documented findings within law enforcement training and DUI detection procedures, making it the most accurate representation of risk in this scenario.