The thing is dude.
RE-NAME THIS MOVIE!
Why?
Because you give everything away. It's so obvious he paints with blood. You didn't have to keep watching to figure that out. You gotta rename it man. Find something more creative, than a "bulls eye" title. Find a title that doesn't give away the concept but still evokes curiosity!
Another suggestion is, when the first lady was murdered. She should be like "Uaghh!!!!" or like, gulping cause it stabbed her or something. Right now it's not satisfying she got stabbed.
Show his paintings more often. The kitchen scene. That way it will set up and emphasize his paintings more. It'll give a stronger pay off when it reveals his secret.
Title Examples:
Scary Painter
Paint Monster
Monster Painter
Serial Painter
Psycho Painter
Red
Maroon
Monster Artist
Psycho Artist
Serial Artist
Roses are Red Damsels are Dead
Artists Block
Now, if you choose a name other than "The Bloody Painter" or "The Man Who Paints With Human Blood", then the audience don't know what they're getting them selves into. The way it's titled now, there's no surprise for us.
You should get a far better response if you rename it.
"Ohhhhhh, he paints with their blood! Now I get it!"
compared to
"Oh yeah, I knew he'd do something like that. Thanks to my habit of reading titles before watching flicks."
Quickly! Rename it! You JUST got front page! You still have a chance!!!!!!!!!!