sherlock , yes , a sherlock story.

lemme think,

==a murder by.....
most advanced weapon -- sound laser gun that caused heart to stop 


==payment to hitman....
new gen money, bitcoin




==phonecalls made using....
private untracable number / anonymous system

==murder scene
a high profile VIP party on a yatch

== suspects
everyone in the party

clue?
a coin on the floor