The Maquis are known rebels and felons and are sought by Starfleet.  His stint as a Maquis was short, he was captured by Starfleet only three weeks into his first mission.  Punishment was imprisonment for treason for 18 months at the Federation Penal Settlement at New Zealand.  It was there that Captain Janeway asked Paris for his help in locating a Maquis ship.  He agreed to help and went on Voyager as an "observer".  When Voyager was pulled into the Delta Quadrant and their head pilot was killed, Paris was given the field commission of lieutenant.  His new career on Voyager has been distinguished, proving he can be an excellent officer.

He is loyal to Voyager and his crewmates.  Tom has risked his life many times for the sake of others.  Most notably, Tom risked himself in an effort to flush out a spy and was extremely instrumental in retaking Voyager from the Kazon. He has become the best of friends with Harry Kim, and has made friends all over the ship.

Tom is quite a woman chaser, and often is flirting with any available female.  He is often turned down, but he doesn't let it bother him.... much.  He has even had a crush on Kes, asked B'Elanna Torres out, and procreated with Captain Janeway when they were mutated due to crossing the threshold.

He set up a holoprogram that the entire crew seems to love, a poolhall named Sandrine's.  The program includes a woman named Ricki that is a favorite of Tom's.  Sandrine's is modeled after a poolhall of the same name in Marselles, France.  Tom enjoys playing pool.  Antique autos are another of his hobbies.  He loves pepperoni pizza with olives, and plain, hot tomato soup.