"He has the ability to take people, to use them...to make stupid movies."

The premise of this thing is silly, a group of jerks endanger a guy, forcing him into a coma. From his coma the guy begins to possess people and make them kill. He kills those who put him into a coma. How does this work? If he could possess people and make them do things wouldn't he just possess a detective and lead him to evidence? Wouldn't he possess a doctor who could help him out of his coma? Why waste this ability killing dim-eyed, amoral dolts?

If I could possess people I might possess the screenwriter and take him to the library and force him to read up on how to devise a better premise.