Titus Rikka is a criminal captured by Raffi and Worf on M'Talas Prime who turns out to be a failing Changeling in a rogue faction.
Titus Rikka is a criminal on M'Talas Prime whom Raffi Musiker and Worf believe responsible for the portal attack on a Starfleet facility. Using La Sirena, the pair track him down and take him prisoner for questioning.
In Seventeen Seconds, they discover that Rikka is a Changeling who is losing his ability to hold a solid form. He belongs to a group of Changelings that has kept fighting the Federation since the end of the Dominion War, and his capture reveals that the attack was a distraction from a larger theft. Rikka was played by Thomas Dekker.