A murder is announced

One of my first Miss Marple books in a long time. I love reading this little old lady and her wide-eyed but “accidental” observations about human nature and facts that lead the police to uncover the solution to the mystery in front of them.

What I don't understand is why Miss Blacklock chose to announce the murder in the first place? Her objective was to get rid of Rudi Scherz, because he might possibly recognise her as Charlotte and not Letitia Blacklock, so why not a quiet murder? Why all these plans to fake a burglary and all that, which is sure to attract attention from the police??