You are extremely lucky that he let you go.
You admitted to consumption, you had the odor, you performed the field sobriety tests. An officer can charge DUI based upon his reasonable suspicion that you were impaired while operating, or in "physical control," of a vehicle, therefore the officer must have been pretty satisfied with the field test results and your overall demeanor.
While it is possible to be charged for as long as the statute of limitations allows, it is very unlikely to be let go and then arrested for DUI if no blood or urine was taken. So, the answer to your question, technically, is "yes." However, the only evidence of your possible impairment is the officer's memory and testimony and any video of the testing you performed that may exist. Given those facts, the most realistic answer is "no."
If you hear about this again, don't speak with anyone about the facts except a lawyer. You would have a defensible case if you were to be charged.
Consider yourself extremely fortunate (you really have no idea how intrusive, expensive and stressful a DUI accusation from an officer can be, even if eventually exonerated). Stay away from areas that invite suspicion, don't drink and drive. Congrats on the college degree.
The above is provided for educational purposes only and is not legal advice nor makes you a client of the Mosca Law Firm, PA. Please consult with a lawyer in order to obtain confidential legal advice that is tailored to your specific situation and facts.
You are very lucky he let you go. What a story. The State will have a hard time with charging you at this stage. You may need to hire an attorney if they do charge you. You were given no tickets, and if he wrote one out for DUI, he should have given it to you. He also had the opportunity to give you a notice to appear, but didn't.
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