malefactor

noun

1. A criminal or felon.
2. An evildoer.

   “‘Pull yourself together, Bradshaw,’ said the lawyer. ‘This suspense, I know, is telling upon all of you; but it is now our intention to make an end of it. Poole, here, and I are going to force our way into the cabinet. If all is well, my shoulders are broad enough to bear the blame. Meanwhile, lest anything should really be amiss, or any malefactor seek to escape by the back, you and the boy must go round the corner with a pair of good sticks, and take your post at the laboratory door.”

   “Though your unseen malefactor’s actions may give the impression of confidence… Vaermina suspects he is terrified his plan will go astray.”