Other mistake: Considering Jules Kopenic was violently murdered and had his arm ripped off, there was remarkably no blood at the murder scene as Kolchak snaps photos of the crime scene.
Continuity mistake: Madelaine's arms instantly switch from crossed to uncrossed when she speaks to Kolchak at Trevi's salon.
Bad Medicine - S1-E8
Revealing mistake: Footage of the Diablero standing up after killing the first rich woman is re-used in the killing of the next rich woman, evident by the shot of the same curtains in the background for both murder scenes.
The Vampire - S1-E4
Continuity mistake: At the press briefing, Lt. Matteo is standing next to Kolchak with a tall reporter in a gray suit standing behind them, but the next quick long shot shows the reporter in the gray suit standing between Kolchak and Matteo.