He’d have to move out of the country, it’s a federal law at issue. (The infamous, and nefarious, Lautenburg amendment.)
When did the Lautenberg amendment go into effect?
The Lautenberg amendment is the one that denies firearms possession to a person classified a “domestic violence offender,” regardless of the penalty. The fellow in the OP is covered by a different clause in the federal morass of infringement on the RKBA; “has been convicted in any court of, a crime punishable by imprisonment for a term exceeding one year.”