Thank you for your follow up.
It would generally be impossible to list all of the jobs and professions that might exclude a felon or make it very difficult for a felon to obtain, since there are tens of thousands of such jobs and professions, however, generally, in some states someone with a felony conviction can obtain a medical doctor license or attorney's license, providing that the person can show rehabilitation and also good moral character at the time person with a felony conviction applied for such license.
Also there are some positions, such as law enforcement, military, etc...that would exclude someone with a felony conviction almost under any circumstances.
So the first step would be for a young person who has violent felony conviction on his record, is to determine as to what job / profession or professional / trade field is of interest to the person and once such determination is made, lets say it is becoming a licensed plumber or licensed electrician, then an direct inquiry / research can be made to determine if it would be possible to obtain a license for the profession / trade with a felony record.
Please let me know if this clarifies it for you or if you have any related follow up questions.