Usually during the first week of school, I would try to have individual conferences with these tough kids.
I'd take this as an opportunity to clear the air and wipe the slate clean.
Often, these students can feel disrespected because their teachers already have preconceived ideas about how they are the troublemakers.
Explain that you respect them and have high expectations for them this year.
Lay the foundation for the student's understanding that you believe in him or her, because you might be the only one who genuinely does.