[s2e4] Chicken, Dynamite, Chainsaw -

The "paper" you are putting together refers to this evidence-gathering scene. Here is the context of the episode:

: Burgess and Roman are assigned to a gun buyback program but discover a weapon linked to a triple homicide. [S2E4] Chicken, Dynamite, Chainsaw

In Season 2, Episode 4, titled " Chicken, Dynamite, Chainsaw ," the phrase refers to a specific version of Rock, Paper, Scissors played by officers Burgess and Roman. The "paper" you are putting together refers to

Chicken, Dynamite, Chainsaw - Chicago P.D. (Season 2, Episode 4) titled " Chicken