Tom Paris comes from a distinguished family of Starfleet Officers. He joined Starfleet, but was involved in a tragic accident that cost several lives. Instead of trying to cover it up, Paris admitted his error and was court-martialed.
Paris quickly joined the Maquis, and served with Chakotay. However, he was captured by the Federation and was sentenced to rehabilitation on Earth. Captain Janeway recruited Paris for Voyager's mission to go after Chakotay's Maquis vessel because of his experience with him.
"Time and Again" - Paris and Janeway are transported back in time to just before a planet's explosion.
"Ex Post Facto" - Paris is accused of a crime he didn't commit and must relive the murder from the victim's eyes every 14 hours.
"Parturition" - Paris and Neelix make unlikely teammates and even more unlikely caretakers to a newborn alien
"Threshold" - Paris shuttles to Warp 10, but his biochemistry changes, turning him to a amphibian-like creature.
"Investigations" - Paris takes leave to join a Talaxian convoy.