Investigation of DUI Cases:
OLS

The One-Leg Stand (OLS) is a test that is performed in a stationary position. If administered properly, the OLS has a 65% accuracy rate in determining a blood alcohol content (BAC) above .10%. Proper administration of the OLS requires a reasonably dry, hard, level and non-slippery surface. If the subject is wearing heels above 2 inches, they should be allowed the opportunity to take them off.

Stage 1: Instructions and Standing Position

The officer will demonstrate the standing position and give instruction at the same time. The officer will direct the subject to stand with their feet together, with arms down at the sides. The subject will be instructed not to perform the test until instructed to do so. The officer must make sure that the subject does understand the instructions.

Stage 2: Instructions for Balance and Counting

The officer will demonstrate and give instruction at the same time. The officer will instruct the subject to stand with their hands at their sides, raise either leg 6 inches above the ground, and count to 30. The correct counting method is: "one thousand and one, one thousand and two, one thousand and three, etc." The subject is instructed to watch their raised foot at all times and count aloud. Before the subject begins the test, the officer must once again ask if the subject understands how to proceed.

Clues

Research has shown that 2 or more clues will yield the 65% accuracy level in determining intoxication above the legal limit. The officer is looking for any 2 of the following clues:

1. The subject sways while balancing.
2. The subject uses arms for balance.
3. The subject hops in order to maintain balance.
4. The subject puts foot down.

Caveat

Original research on the application of the OLS indicated that those individuals over 65 years of age and those persons with back, leg, or middle ear problems had difficulty performing the OLS. In this instance, defense counsel should argue that the weight of this test is in question and should be considered in determining whether the subject was actually intoxicated.