I don't get how decapitating and dismembering the body with an electric saw is a mark of a professional. It seems like a very messy and over complicated way to kill someone.
What if the person was killed first with another simpler method, and the electric saw was used after, for disappearing purposes?
"Some time after, the assailant killed Mr. Saleh, decapitated him and dismembered his body with an electric saw."