Thank u so much for ur reply ...
If you are about to begin training as a police officer, I guarantee that you will be taught how to protect yourself, as best as possible, against exposing yourself to HIV.
I could advise you on ways to keep yourself safe in "normal" situations, but as a police officer, there are bound to be times when you simply do not have time to take precautions.
If you are concerned about acquiring HIV on the job, perhaps it would be best, before you begin training, to discuss your concerns with the instructors and other officers. Their first hand knowledge in this specific matter is much greater than mine.