This is what happened to someone I know. He made a single mistake, hanging around with the wrong crowd, and then even though he was trying to change his life, he kept getting screwed over by "the system". There were lots of issues related to going to halfway houses or going to jail. He got sick and missed an appointment with a parole officer, which caused him to lose his job, which caused him to be thrown back in jail. He was trying his best to follow the rules, but after losing his temper and threatening to attack someone who had been bothering his father, he eventually ended up getting thrown out of the country (he lost his permanent resident). Obviously he made a few bad choices, but if someone is making a concerted effort to change his life, it feels like they should be afforded more of a chance to succeed.