Hello. I am reading through this and will be commenting as I go.
Opening page, initial thoughts are that all these action lines can be condensed and written a bit more fluidly - I can see cases of double information and things that cannot be seen or filmed.
It appears to be written, awkwardly for lack of a better word - It makes it difficult to read and get into the story.
Example "There’s a handle stuck in his back. Looks like the handle
of a knife." - There is no need for the word "There's" - and why not tell is the handle is a knife in the first place, like this - "A Knife handle protrudes from his back"
OK, Roger is the in the crime scene showing the detective where the body was found - this would not be the case - the crime scene would be sealed off for all civilians - they would be interviewing him OUTSIDE of the cordon.
Now she has placed him under arrest just because he was the last person the victim called. This doesn't seem right to me, is that enough evidence to arrest someone? would they not just bring him in for questioning?
At this point I'm out. The action needs work to make it more readable.
Good luck in your writing