how does ctu get away with torture in season 3 of 24?

I am on ep. 14, and this is the second time "Richard" has come in with
his special shot kit, that is obviously painful. If cruel and unusual
punishment is protected by the constitution, how is this possible in a
show set in the 21st century?

I understand this is a TV show, but it bothers me because it disrupts
the "American" forces mood. Someone please enlighten me. Thanks!