So long as you may legally possess a firearm, no.
Contact your local police.
You will have to consult a lawyer for a current, correct and legal answer.
First, if that is not legal where you live, know that you may go to jail. Second, your chances of buying a stolen gun are higher than buying a gun from a licensed dealer. That means you encourage people to break into other peoples houses and steal- and, if you get caught with a stolen gun, you may go to jail. Finally, if there is a problem with the condition of the gun, it is very hard to return it to someone you bought it from "on the street". Isn't that about the same if you buy anything "off the street"? Your chances of buying a stolen TV or vacuum cleaner are greater than if you buy it from a reputable dealer. That only encourages the dealer to overcharge you, but it is easier to return, if he will let you. Unfortunately, it is my opinion that it is better to explain to a judge why you inadvertently ended up with a "hot" gun, than to GOD why you didn't have a gun at all.
Was thinking of buying a used firearm to defend my home from invasion. But how do I know if its stolen? Call your local police department and have them check it in NCIC. You may have to bring it in so they can confiscate it if it is stolen.
Yes, if you were convicted of it. It's a felony charge.
From a previous question, I understand that you are concerned that a gun you purchased may have been used in a crime. First, buying a gun at a gun show really has no greater chance of that being so than buying a gun at a dealer's shop, or buying one from a local private seller. You had asked about registration- in MOST of the US, there IS no registration of ordinary rifles, pistol, and shotguns. There is also no way of knowing if a random gun was used in a crime. If you are concerned with a firearm having been stolen, contact your local police department, and ask if they will check your guns serial number against the computer listing of stolen property. They will usually want to have possession of the firearm when they do that.
No! Actually, that depends on where you are and what the charge is. In the U.S. any felony will prevent you from buying a gun legally, but misdemeanors do not, except for misdemeanors of domestic violence.
my knowledge on the sugject is that if a person had no prior knowledge that it was stolen then if the police find the gun and see it is stolen then theyll return it to its rightful owner, this goes for any property that they believe is stolen but that the police do not believe is the owner. so most likely a person would not get any punishment, but that might be effected by local or state laws or it could be effected by the specific situation.
what gun are we talking about here
You can't- unless you are a law enforcement officer. However, if you are concerned that a gun you are considering buying may be stolen, see if your local law enforcement will run the serial number for you.
An arrest if no charges are filed may not prevent you from buying a firearm. You cannot buy a gun after a plea of guilt or finding of guilt for a domestic violence related offense even if just a misdemeanor.
Contact your local police department and give them the serial number. The Police can check on the stolen gun list maintained by the BATFE. If the gun is stolen, the Police will conficate the piece and begin investigation of how it was acquired.