Roger Anthony Lemke is a Canadian actor. He is known for portraying Brian Becker on CTV's fantasy drama The Listener, Dan Malloy on Bravo's police drama 19-2, and Ryan Elliot on Hallmark Channel's fantasy comedy-drama Good Witch. In French Canada, Lemke is known for playing David Rothstein on Radio Canada's comedy-drama Les Hauts et les bas de Sophie Paquin.He is currently appearing as Three (Marcus Boone) on SyFy's science fiction drama Dark Matter.