When they're talking on the football field it is actually a Canadian regulation field.
The newspaper states that the murders took place 28 years apart. When Tony flashbacks to the original crime scene, the song "So In Love" by OMD is playing on the car stereo. This song was released in 1985 and 28 years later would be 2013.
When Tony flashes back to being in the car with his girlfriend in the '80's, the song playing on the car stereo is "Don't Walk Away," by The Chain Gang of 1974. This song was released in 2010 (although it does sound similar to OMD from the '80's)
Sam's wife's name is Kate Robb. In the end credits, her younger self in flashbacks is listed as Young Sue Robb.
The name of the girl murdered twenty-eight years ago is written in the newspaper clipping as Allison Taylor. In the end credits, the character's name is written as Alison Taylor.