Fringe (2008)

S04E02 One Night in October

With a string of victims falling prey to a cunning serial killer "Over There," the Fringe Division "Over Here" is called in to help. As tensions rise and innocent lives hang in the balance, they discover a doppelganger of the suspect—a Forensic Psychology professor—who complicates their investigation. This unexpected twist prompts the team to explore the controversial idea of transporting civilians to the alternate universe in a desperate bid to capture the killer and protect the vulnerable.