The start of many a Detective Drama.
We see the murder from the murderer's point of view.
Leads to a Reverse Whodunnit, unless the Murderer P.O.V. is composed in such a way as to keep the killer's identity a secret (for example, via an Over The Shoulder shot or an actual P.O.V. Cam shot).
The most common variety, mostly exlusive to murder mysteries, is when the victim casually greets their killer [...] [tvtropes.org]