Conversation so far:
Why was Erich Mielke imprisoned?
Mielke was arrested and prosecuted for the murders of Captains Anlauf and Lenck.
Was Erich Mielke found guilty?
Erich Mielke was convicted on two counts of murder and one of attempted murder.

Question: Was he ever jailed?
Self-contained rewrite: Was Erich Mielke ever jailed?