Some rights need to be given up if one is convicted of a crime, especially if that crime involved any sort of violence. So an ex convict should not have the right to own a gun anymore. The threat to society is more important than the individual rights of someone who's broken the law that way.
In most states, ex-convicts have to wait years after their release to have their voting rights restored, and many are disenfranchised for life. Yet they often have their right to bear arms automatically reinstated when they leave prison, with little or no review by judges. In several states, they include people convicted of violent crimes, including first-degree murder and manslaughter
Ex-convicts shouldn't own a gun, especially if they are felons. Criminals lose their rights for a reason, because they destroyed other people's rights in the first place. Ex-convicts, as long as they were felons, have no business owning a gun because they will use the weapon to commit more crimes or even kill people.
Ex-convicts should not be allowed to have a gun for at least 5 years, and even then they must take a course and pass a mental test to see if they are fit to own one. Also, it should also be based on what crimes they committed. If it involved the use of a gun, then the time limit may extend even further until they are allowed to own a gun.
When I say that ex-convicts should not own a gun, I am mostly talking about the violent offenders. But, if we exclude all ex-cons it would be a step in the right direction for getting guns off the streets of the United States for good, and I am all for that.