The Udara Legacy
Newcomers who get suddenly violent and a plot against Overseers forms the basis for this final movie in the Alien Nation series. It works by some kind of post-hypnotic setup. The problem is some human has found the key that turns on their killing implanted message.
The first woman activated is a Newcomer policewoman who ends up killing an man that is due to be a witness against a human that is due to go on trial. More die after that, always killed by Newcomers.
Buck decides to enter the police academy. There's a lot of anti-alien prejudice there, though.
It's shown that Cathy knows more about the Udara then she lets on. And it's not the only secret she's hidden from George. Emily gets involved and the whole thing shows the power of unjust control, hatred and greed.
All five movies in this series are really good and speak to problems still going on today.
My Alien Nation Index Page