Crime In E Minor

The detective looks at the body and says “Round up every violinist.”
He is holding a smashed instrument, and his conclusions would be sound if he were correct about one thing: that is a viola, not a violin.
They dust it for fingerprints… none at all.
I wore gloves, you see.
Yes, it was me, dear reader. I am the murderer.
And that is my viola.
The violinists come in, one after the other, but each has an alibi.
It is a year later, he is no closer to solving the case.
Good.
Because my new viola thirsts for blood.