I'm a brand new GM and decided to run my first campaign with Star Wars: Edge of the Empire. When helping my players create characters I told them they should make they make like the crew in firefly, Smugglers with morals, and they liked the idea of that.
When we started I used a supplement material to get me started since I was completely new to the GM scene. The first session went well and I started to make my things for my players to go do. Now when the second session came around things started to change a bit. They began to become more chaotic and evil with the way they play.
In the third session I set them up with a mission to infiltrate a Sith medical research facility to retrieve a plague antidote with one of the players backstory friends. They went to do the mission and found out that the research facility was underground beneath a hospital. They infiltrated it and succeeded in getting the antidote, which was rakghoul plague, but also found out a sample of it and a few rakghoul that were experimented on. instead of just leaving they took the plague sample(ill get into that later) and release the rakghoul into the hospital. Then as they left they proceed to set off explosion and murder as many people as they could in the hospital as they tried to escape. Then when they finally escaped they decided turn on the players backstory friends and murder them in coldblood, lead by the player with that backstory. So with that they wanted to try and reproduce the plague sample and antidote to infest planets and sell the antidote for massive profits. I wouldn't really have a problem with this but this really went against their backstories and the way their characters.
They continues to do evil like things in the forth session and this is where I decided to take action and put the consequences of them screwing with so many people in by having a bunch of bounty hunters hunt them. The forth session ended with the bounty hunters just barely being able to knock them all out all the players to turn them into a hutt they messed with in the first session.
Alight so this is were my question comes in. I have no idea where to take this game at this point. I have an idea on what to do but, one I don't know if they will take it because they tend to betray/murder everyone they meet, two I want to take into the vein of a more devious thing with them building their own drug empire but it felt like it would go against the way the characters should be and how they should of acted (even though the players actions say otherwise) plus I brought it up with one of my players of taking it in that way and he said no way because his character would never do that (he plays a doctor who hates the sith since they corrupted the politics on his planet and in his backstory is a mary sue good guy but hes the one who came up and wanted to reproduce the plague and infest innocent planets for profit). So any advice? I was thinking about scrapping this campaign and starting a new one to run with my players with a fresh start. Most of these issues came up due my lack of GM experience so I'm mostly at fault for this. Any advice is welcome, Thank you all!