Supposed to last 45-60 Min. What should I expect? It will be before current officers and academy staff.

Thanks,
SorryOciffer

Always go in prepared for the worst. If anything less happens, you've got it covered.

Expect a variety of questions. Maybe some "What would you do if this happened?" Some general knowledge questions. There may be questions about answers you put on your application/background, work history, family history, credit history etc.

Take a long deep breath before you go in and try to relax. They know you're going to be nervous.
Keep your eyes and ears open. Listen to what they say. Answer the questions honestly and sincerly. Look at each person as you answer the question.

DON'T joke around or make comments that may be taken the wrong way.

Thanks Firedog.
SorryOciffer

You want to appear confident, but not over confident.
Keep your answers short and simple.  If they ask you to elaborate, do so.....but don't go on and on.
They will probably ask you some questions that cover use of force, accepting gratuities and witnessing wrong doing by other officers.
When I have sat on oral boards I have always liked the candidates that appeared to think for a second before speaking.  
Don't just give the answers that you think they want to hear.  And what ever you do....stick to your answers.

Good luck.