Another way to say "The person is in jail?"

I once heard a woman proudly announce that her son was "involved in the criminal justice system." It took some further questioning and conversation to get her to admit that her son was incarcerated in juvenile hall.

A black person.

Locked up, in clink, in the pokey, residing at Her Majesty's pleasure (UK)

He/She has been incarcerated.
He/She has been sent up the river.

"Gone away on a little holiday." Perhaps?

They are presently unavoidably indisposed.

He/she's in school 😐

They're taking a break

He's in the boob.

Incarceration

incarcerated

Remember all those 70s thrillers where the man 'goes abroad' and arrives after xxx years?!?

In the clink
Jailbird
Inside
penal servitude
Incarcerated
Doing time
Porridge
Pokey
Chokey

ME IS MARRIED

he/she is away on extended business, he is / she is a guest of the government,

Spending the night in the Grey Bar Hotel

or institutionalized or imprisoned or ...
many.

on ice

Uh..in the lock box or, in the pokey?

the cooler

They're in the slammer

Locked up