Catch Me When You Can

A man and woman moved silently down an alley.
"We've got to be quiet, dearie." she whispered. "The bobbies 'ave been all about lately."
"We won't be caught, I'll wager." he replied confidentially.
"'Ow can ye know that, then?"
"Don't you know, love?" he hissed. "I'm Jack the Ripper!" Her eye caught the glint of steel in the foggy lamp light.
She had less than a second to register his words before the cold blade sliced through her jugular, halting her scream before it could be heard.
Within moments, his deed was finished and he'd vanished into the shadows, unseen.