Officers said they stopped Cassidy after seeing his Mercedes swerve on State Road 91 just after 6 p.m. on Nov. 3. They said Cassidy was weaving across lanes and cut off another car, nearly causing an accident.
After Cassidy was stopped, officers said they smelled alcohol when he was talking to them. He told officers that he had a glass of wine at lunch and a hydrocodone tablet later in the afternoon.
When he got out of his car, officers said Cassidy was unsteady on his feet and failed several field sobriety tests. Breath tests at the St. Lucie County jail showed his blood-alcohol content at 0.139 and 0.141, above Florida's legal limit of 0.08.
Officers searched his car and said they found a bottle of bourbon that was half-empty in the back, according to an arrest report.
Cassidy, 60, was arrested and charged with driving under the influence, failure to maintain a single lane and open container violation.
Cassidy has pleaded not guilty and plans to contest the DUI charge.