Don't know why on earth the BBC are referring to it as homicide, it's murder surely?
Anyway - it's a good thing
I also think people are less likely to get away with murder these days what with CCTV, mobile phones, facial recognition and vehicle tracking so it might be that thats making people think twice, for a certain type of murderer anyway. Obviously a domestic murder is something else.
Another thing that might be influencing this is improved medical care and life saving.