Sam and Dean learn about Rowena killing the art gallery patron the day after it happens, they read about in a newspaper's online article which was released the next day since it already had the autopsy results. Even driving non-stop it would take at least 24 hours to get from Lebanon, Kansas to Portland, Oregon. Which means at a bare minimum Sam and Dean arrive in Portland two days after the murder in the art gallery, yet when they arrive at the gallery there is a forensics team there taking photos and detectives are examining the scene as if they had just arrived and were still processing the scene, something that doesn't take two days to do.
When Rowena rips open Sam's shirt, you can see his anti-possession tattoo. Around the tattoo, you can see a border from where they put on the non-permanent tattoo.