My question involves criminal law for the state of: Virginia

My ex husband was convicted of sexual assault (all misdemeanors) in March of 2009. He served 8 months in a county jail and was released in November of 2009. Since then, he has been on parole and/or probation. His probation officer has told him that he is considering releasing my ex from probation early next year. My ex has done all that he has been asked to do, such as attend sex offenders' classes, etc. He has not been in any additional trouble. So, here are my questions:

1) Does Virginia have the tier system in place for sex offenders? I know some states do, but not if Virginia does.
2) How can he figure out which tier his convictions fall on?
3) Is it ever possible for him to get off the registry?

Thanks for your help!!