Many DUI arrests begin with a police traffic stop. This is often based on a police officer's belief that he/she observed a minor Vehicle Code violation while driving. What's important to understand is that any police traffic stop must be for lawful reasons. Your PA DUI lawyer will review your case to help you determine whether a traffic stop was conducted lawfully.nnOnce you have been stopped, an officer may ask you to step out and submit to Standard Field Sobriety Tests (SFST). SFTSs are not mandatory, are highly subjective, must be properly conducted, and are not a “pass/fail” test. If you agree to SFSTs, the officer will likely have an opinion as to how you performed.nnYour DUI attorney will review the circumstances of any SFSTs to determine whether they were properly and lawfully done. Whether the officer's opinions and conclusions from the tests should be relied upon. Based on the SFSTs and the officer's opinion of your impairment, you could then be arrested and asked to submit to chemical testing. chemical testing is used to detect blood-alcohol content (BAC) or the presence of drugs.nnWhile Pennsylvania law provides harsh punishments for those who refuse breathalyzer test or chemical testing under certain circumstances, this does not mean that police officers have the right to require chemical testing for all motorists they encounter. For this reason, your attorney will review all circumstances of your arrest. A diligent DUI attorney will look into your breath test, chemical testing, or an alleged refusal to submit to chemical testing. A good DUI lawyer can help you determine whether these proceedings were conducted lawfully and properly. A DUI arrest doesn't necessarily have to lead to a DUI conviction.