Matthew Ross

Matthew was a lobbyist in the Collier organization who advises Shawn after Jordan Collier's death. Matthew ran the day-to-day business of the 4400 Center and it was hinted Collier gave him specific instructions of what to do.

Early episodes in the third season suggested that Matthew knew more about the 4400 and Jordan Collier's assassination than he had revealed. When Isabelle Tyler was contemplating suicide, Ross told her she was nearly invulnerable, but offered her a syringe that he claimed would kill her. In a later episode, a similar toxin was given to Tom Baldwin from the future in order to neutralize Isabelle.

Matthew was later murdered by Isabelle when she inflicted an instantaneous stroke upon him. He had manipulated her for some time, and informed her that her purpose was to destroy the 4400. He implied that his loyalty lay with a faction from the future, one that opposed the 4400 project. This faction would be described to Tom Baldwin by the future people, and were described as cold and brutal in their methods.

In the fourth season episode "The Marked", it was revealed through Curtis Peck's ability that Ross was among a ten-strong group of prominent individuals in society who have had their consciousness "hijacked" by the 4400-opposed faction. A side-effect of this operation left a mole underneath the subject's left earlobe, along with a vaguely X-shaped mark (hence the title of Curtis' Independent film and thus the episode). This mole was never actually visible in any scenes where Matthew was present, but it was explicitly revealed that he was the first known "Marked."