A criminal defense lawyer can examine the circumstances of your arrest and determine whether police officers violated any laws or procedures or whether there are any issues with the evidence used against you. For example, your attorney may be able to argue that an officer did not have a reason to pull you over in the first place, or they may show that the equipment used to measure your BAC was not calibrated correctly. Your lawyer can also help you determine what options may be available to reduce your charges or sentence.