The Killer Princess 1923

In this episode, we are travelling back to 1923, to the Savoy Hotel London. On the night of a thunderous storm that rocked the city, following a loud and raucous argument, a wife shoots her husband dead. She is discovered with the gun in her hand and admitted to the murder immediately. She committed the crime, no doubt about it. Then how was she found not guilty at trial? 

This case has it all, privilege, money, royalty and affairs.