There are a number of roles in the justice system, for example:

Accused*
Arresting Officer
Court Clerk
Court Interpreter
Court Reporter
Court Services Officer
Crown Attorney/Assistant Crown Attorneys
Defendant**
Expert Witness
Judge
Justice of the Peace
Lawyers
Criminal Defence Counsel
Criminal Duty Counsel
Family lawyer
Legal Aid Ontario
Media
Native Worker
Paralegal
Probation Officer
Respondent/Applicant***
Surety
Trial Coordinator
Victim/Witness Worker
Witnesses

* Relates to criminal proceedings

** Relates to Provincial Offences Act proceedings

*** Relates to Family proceedings