Try this--
for feds
http://www.bop.gov/
for state
http://www.vadoc.state.va.us/offenders/
Click on inmate locater on both of these pages. The feds will give you info on released inmates (release date), the state doesn't.
There's a bunch of online services that will do criminal backgrounds for a fee, I've never used one though.I've got rentals and I've got a friend that does the credit check for me. I run'em through the arrest/ticket search HERE to see if they've done anything I can't forgive and then run 'em through the sex offender one (
http://sex-offender.vsp.virginia.gov/sor/ ) just to be safe.
I hope you're not a fat girl who's looking for some snake con you think could give you some pen pal love. These stories rarely turn out good,