Do not forget that if you use an acronym in your narrative report you must explain it the first time. For example, "Field Training Officer (FTO)."
Be consistent with the titles you give all actors in the report. For example, I have seen reports where the bad guy was called a citizen, suspect, person of interest, violator, perpetrator, arrestee, detainee, interviewee, and nearly all in one police report! Find out what is acceptable with your department and stick to it. We are not having a workout with the criminology thesaurus.
Final Advice
A very wise old sergeant once explained to me the benefit of developing your own trademark. He told me that in a large department it can be hard to surface to the top and be noticed for better assignments such as detective. But excellent officers are often recognized by the quality of their police reports, which become their trademark.
If you write an excellent preliminary investigative report you will be known by others who use your product: the detectives, the district attorney, and later parole/probation officers, for example. Your report has many end-users. Start off your career with a goal to prove your worth by the quality of your report writing.