In the scene in which Mars killed his mother at the Wallkill Correctional Facility, he was actually holding a "blood sponge" in his hand. The sponge was soaked with blood so that when Mars squeezed it, it appeared as though blood was oozing from the knife wound.
The Highland Lakes Fairgrounds scenes were all shot at a conservation area on the outskirts of Toronto. The Set Decoration Department rented and trucked in all of the amusement park rides and attractions for the day.
A portion of the footage from outside Starla Rowland's house was re-shot months after the original shoot date. Because it was winter by this time, all of the visible snow had to be melted and washed away from the road and front lawn for the sake of continuity.
The mansion featured in this episode was filmed at a stately home in Toronto's Humber Valley. To simulate the bullet from Mars' shotgun hitting the ceiling when he was tackled by Charlie at this location, the SPFX Department installed a plaster rig on the ceiling. When the cue came each take, they would release a small avalanche of plaster and dust that would fall to the floor.
The clock that Mars smashed at the mansion was built out of "candy glass" specifically for the scene. Twelve pieces of this easily breakable glass was made for the clock and was replaced for each take.