In the grocery scene, the items on the shelves and fridges are modern, like Snapple, etc. Also, there's a grading system card on the front window.
Michael Rooker shouldn't be in the final scene when Bonin dies because Detective St John passed away the year before.
Every city shot contains background vehicles that are clearly makes and models contemporary to 2009 when the movie was filmed. Bonin was apprehended in June 1980.
In the first grocery scene where Bonin "meets" Kyle, the display cooler behind him has Starbuck brand Frappichinos on the top shelf. This movie is set in the late 1970's and was way before this product came out, Frappachinos were introduced in the late 1990's.
When Kyle walks home after fighting with his girlfriend, there's a Toyota Prius parked in the street.