Coffee and death with a spice of magic

What seemed a typical visit to the coffee shop for Cassinda ended up in a disaster when a man was murdered and the detectives found a trace of her magic on the body.

_ My entry for the Coffee and Crime Contest.
Prompt: You walk into your usual coffee shop to grab a cup, but as you enter, someone suddently nudges you on the shoulder and says, "you've finally arrived, our main suspect." That's when you glance around to see yellow duct tapes all over the place.