Seizure without probable cause

The defendant was asleep in a parked car at 2:19 a.m.  The officer noticed the car on the side of the road with an individual sitting behind the wheel, with the engine on, and made contact with my client.  After noting signs of intoxication, the officer arrested the defendant who then submitted to a breath test with a result of .193.  I reviewed the report carefully, and then at the Express Consent driver’s license hearing, asked the officer questions as to whether he left his red and blue emergency lights on.  The officer admitted that they were.  I also clarified with the officer that he did not see that the defendant had committed any violations of the law before he made contact with him.  Then when I met with the District Attorney, I argued that the activation of the red and blue overhead lights requires an individual to pull over and constitutes a seizure under the Fourth Amendment.  This seizure was without probable cause to believe that the defendant had committed any criminal offense and would mandate dismissal of the case.  The District Attorney was concerned enough that I would prevail on this argument that he offered a plea bargain where the case would be dismissed in its entirety after one year if the defendant fulfilled certain terms and conditions.