Love interest nearly always weakens a mystery because it introduces a type of suspense that is antagonistic to the detective's struggle to solve the problem. It stacks the cards, and in nine cases out of ten, it eliminates at least two useful suspects. The only effective love interest is that which creates a personal hazard for the detective - but which, at the same time, you instinctively feel to be a mere episode. A really good detective never gets married.
Raymond ChandlerThere was a desert wind blowing that night. It was one of those hot dry Santa Anas that come down through the mountain passes and curl your hair and make your nerves jump and your skin itch. On nights like that every booze party ends in a fight. Meek little wives feel the edge of the carving knife and study their husbands' necks. Anything can happen. You can even get a full glass of beer at a cocktail lounge.
Raymond Chandler