The fifth (sixth if you count the original film) Alien Nation movie is up on Hulu:
Matt and George investigate a series of strange occurrences involving newcomers, who are found to be programmed to carry out someone's dirty work. The method by which they are brainwashed dates back to the slave ship's rebellion group, the Udara, who we find Susan is a part of. Susan and George's lives are further disrupted when Buck enrolls in the police academy (IMDB).
I miss Alien Nation on a regular basis. Their mix of a classic cop series with the Scifi complications and alien family drama made this show the classic it will inevitably become. This movie is a must see for all!