In Ohio, the offense is called Having Weapons While Under Disability (O.R.C. 2923.13). It bars possession of a firearm or dangerous ordnance by any person who:
1. is a fugitive
2. is under indictment for or has been convicted of (or adjudicated a delinquent child for) a felony offense of violence.
3. is under indictment for or has been convicted of (or adjudicated a delinquent child for) a n offense involving the illegal possession, use, sale, admiinistration, distribution, or trafficking in a drug of abuse.
4. is drug dependent or a chrinic alcoholic.
5. a whole list of mental illness issues, mainly involving commitment to a metal hospital.
The real trick is that technically, any person who has been convicted of a mnor misdemeanor Possession of Marihuana can legally put you under disability. So, get busted in college for possesion of a joint, end up with a felony years later when you get caught for speeding on the way to the range.
Now, there are provisions under the law for being relieved from disability after you successfully complete your sentence for the disabling offense. You just need to know atht you have to jump through the hoops. Many people don't.