As others have mentioned "Good Morning/Afternoon/Evening" will suffice. It is common practice in any US military type training including police training to address civilians as Sir or Madam/Ma'am but it is not expected from civilians. If you were graduated from law school and an officer of the court then adding Cadet would be appropriate, since you outrank them.
For anyone when addressing a uniformed police officer "Officer" is appropriate not Sir or Ma'am, it shows respect for their authority and can help you avoid a ticket.
For an Officer of the court such as DA or Judge it would be appropriate to use there title. Detective, Lieutenant, Captain, Officer (for street Cops) etc...
For a defense lawyer I believe that using the appropriate title is only expected on official business such as questioning for a case.
in the state of california, state bar, harrison street, san francisco, california...a lawyer is only an officer of the court when in court and a law student is only an officer of the court when in court as a law clerk or in special circumstances a junior co-counsel in the lower court
outside of court, in california, they are not court officers, and in no way are they superior to any police officer or cadet
many a lawyer never spend much time, or any, in court
in a famous case in my city, which i won't mention since it has not been settled yet, the mayor of the city was pulled over for drunk driving....i think he was .05 and had half a glass of wine but still impaired...he tried to pull rank on the cop
the mayor has absolutely no authority over the cop on the street if he sees the mayor, popular and very wealthy in his case, driving impaired
the mayor is like any other citizen
now i am talking of a certain city in the state of california
i have no idea how another city would handle it, and especially how another state would handle it
from a previous post, sure it's not a good idea for a police officer to piss off a lawyer or judge, but it is not a good idea for a lawyer or judge to piss off a cop
btw, the mayor, also a superior court judge, was voted out overwhelmingly despite a close personal relationship with the president who he brought to his city for a speech
i am not aware of georgia, as i mentioned earlier on that different states have different rules