Douglas Aarniokoski

• Birth Name — Douglas Aarniokoski • Other Names — Arnold Cassius • Occupation — Television director, television producer • Years Active — 1991–present

Aarniokoski got his start as a production assistant on Rambo 3. He continued as production assistant on Turner & Hooch and as a personal assistant to Tom Cruise on his 1990 film Days of Thunder. He then worked on the 1992 horror feature Doctor Mordrid, as the first assistant director. He went on to serve as assistant director on several other films such as From Dusk till Dawn, Living Out Loud, The Faculty, and Spy Kids. Later he began serving as a second unit director for features such as The Medallion, Once Upon a Time in Mexico, and Resident Evil: Extinction. His directorial debut was with the 2000 action film Highlander: Endgame. His other credits include Animals and The Day. He co-wrote and directed the 2013 horror Nurse 3D. Aarniokoski has directed 8 installments of the CBS series Criminal Minds since 2011, while directing two episodes of The CW's Green Arrow origin series Arrow and one of its sister-series, The Flash.

During the first season of the FOX series Sleepy Hollow, Aarniokoski directed the 7th episode, "The Midnight Ride". In winter 2014, he joined as supervising producer and main director on the show. He has since directed the second-season episodes "Go Where I Send Thee...", "And the Abyss Gazes Back", "Kali Yuga" and "Awakening".

In 2015, he joined the new CBS series Limitless, as supervising producer and director. The show will be run by former Sleepy Hollow co-worker Mark Goffman.

• Year — Title — Director — Writer — Notes • 1993 — Puppet Master 4 — Direct-to-video • 1994 — Puppet Master 5: The Final Chapter • 2000 — Highlander: Endgame • 2009 — Animals — Credited as "Arnold Cassius" • 2011 — The Day • 2014 — Nurse 3D Acting roles • Year — Title — Role — Notes • 1997 — Austin Powers: International Man of Mystery — Dr. Evil's Telephone — Voice, Uncredited • 1998 — The Faculty — Brun Coach • 2000 — Highlander: Endgame — Kirk

• Year — Title — Notes • 2011–2026 — Criminal Minds — 12 episodes • 2013–2015 — Sleepy Hollow — 6 episodes • 2013 — Hungry • 2014–2015 — Arrow — 2 episodes • 2015 — The Flash — Episode: "Rogue Air" • 2015–2016 — Limitless — 4 episodes • 2016 — American Gothic — Episode: "The Oxbow" • 2016–2017 — Bull — 4 episodes • 2017–2024 — Star Trek: Discovery — 5 episodes • 2018 — Timeless — Episode: "Mrs. Sherlock Holmes" • Instinct — 3 episodes • Salvation — Episode: "White House Down" • Star Trek: Short Treks — Episode: "The Brightest Star" • 2018–2023 — S.W.A.T. — 5 episodes • 2019–2024 — Blue Bloods — 10 episodes • 2020 — Charmed — Episode: "Curse Words" • 2020–2023 — Star Trek: Picard — 5 episodes • 2021 — Clarice — 2 episodes • 2024 — Tracker — 2 episodes • 2025 — The Irrational — Episode: "Another Man's Treasure" • Leverage: Redemption — Episode: "The Polygeist Job" • 2026 — Star Trek: Starfleet Academy — 2 episodes