RT = Russian Television.
A truly secret arrest we would not be hearing of. Why, you are asking? Because a secret arrest would be secret. When we are hearing of arrest, it no longer is being secret. Da?
I imagine that I read of about 4% or fewer of arrested in my community. They may not be secret, but they are not publicized.
There is a deterrent effect for arrests: no one likes to be arrested, so at least some people do not commit crimes because they do not want to be arrested.