Each main character (Kara, Connor and Markus) has their own theme music composed specifically for them. Which, like the camera work, was a way to differentiate one character from another.
Bryan Dechart came up with the serial number on Connor's jacket, 313 248 317-51. He explained in a Twitch stream that 313 stands for the Detroit area code, 248 for his home area code, 317 for his birthday, 5 for the number of people in his family, and 1 standing for the first Connor. The last number goes up by one every time a Connor dies.
In the chapter "Battle for Detroit" when walking with Kara & Alice a movie theatre can be seen. "Heavy Rain" is listed as one of the movies currently showing. "Omikron: The Nomad Soul" is also referenced.
Amelia Rose Blaire (The Tracis) and Bryan Dechart (Connor) are married in real life.
Audrey Boustani, who plays Alice, also plays Emma, the hostage girl at the beginning of the game.