During investigation by police: person of interest, suspect, alleged offender
After being charged: accused person
On local court documents: defendant
At court:defendant, accused person
When defendant pleads guilty or is found guilty by the court:offender
** In the case of juveniles, the alleged offender is usually referred to as "the young person" up until they appear before the Children's court. In Criminal proceedings at the Children's Court they may simply be referred to as "the person"