Detainees are not always guilty; they may be held for various reasons, including investigation. Despite being a detainee for weeks, he was later found innocent of the charges.
Pro Tip 2/3
Temporary Status
'Detainee' implies temporary confinement, not a long-term or permanent situation. The detainee awaited his trial date, hoping to be released soon.
Pro Tip 3/3
Not Always Criminal
Being a detainee doesn't necessarily mean the person committed a crime; sometimes the reasons are political. The journalist became a political detainee after her controversial report.