once you have a criminal record, do you become basically unemployable?
To a certain extent, I'd say yes. However, it really depends what crime you committed. If you're on the sexual offenders list, you probably won't even be able to work at McDonalds. Obviously, murder, kidnapping, etc, will most likely keep you jobless; the same goes with any offense against a child. Most human service jobs (Doctor, teacher, nurse, social worker, etc.) require a clean record. Anything other than a minor traffic violation can preclude you from any of these jobs.
When I landed my internship, I had to go for a fingerprint scan (DOJ, FBI and sexual offenders list). On the application, it stated, "any individual who has been convicted of a crime, other than a minor traffic violation, including misdemeanors, felonies and convictions that occurred a long time ago, cannot work or be present in a XXX facility unless a criminal record exemption is requested and granted."
There are 50 crimes for which an exemption cannot be granted. The non-exemptible crimes include, but are not limited to: Willful harm or injury to a child,
Incest, Child sexual molestation, Sexual battery, Murder, attempted murder, voluntary manslaughter, Rape, Crimes requiring registration as a sex offender
Mayhem, Kidnapping, Arson, Torture, Carjacking, Robbery, Advertising or distributing child pornography, Sexual exploitation of a child.
