Adding Institutions into my Trailer

I will be adding a short Warner Brothers clip at the start of my video. I am doing this as it is shown in style models i have researched and i want to make my trailer as real as it can possibly be with it also looking professional.

I looked at style models following the genre i have chosen for my trailer which is horror/thriller i viewed the following: The Conjuring 1, 2 and 3, The Call, IT, Don't Breathe and more. 
However, i chose the small clip from the start of the trailer The Conjuring 3...