I bought a handgun in the state of Missouri for my boyfriend. I had the criminal check done in my name, since it was a gift.
No worries there. You purchased the gun. The NICS check is a requirement of purchasing it from a dealer. It is not a registration, and it does not link the gun to you beyond that point of purchase. You could legally sell it, give it away, or otherwise dispose of it to any
non-prohibited resident of your state -- or sell it to (or through) a dealer in any state). All that NICS does is assure the dealer that you are not a person prohibited from buying that gun at the moment of that sale. The only record of you having purchased that gun exists on the paperwork stored in the dealer's filing cabinet.
Now, our relationship is coming to an end, and I want the handgun back for several reasons: I don't want any future trouble with the gun since it was criminal checked in my name,
The fact that your name was on the original transfer paperwork is not damning evidence against you in the case that he does something unpleasant with it. The only "trouble" you might have is a visit from the police during the investigation of any future crime in which that gun was recovered.
What would happen is this:
1) IF they find a gun, and DON'T know who owned it or fired it, they'll contact the manufacturer who will give them the name of the dealer who first sold it. That dealer will give them the name of the first purchaser of it. (Assuming that's you.)
2) They'll contact you and ask you about the gun. You tell them the truth -- I gave it as a gift to my ex-boyfriend on or about such-and-such date.
3) They say, "thank you," and go talk to him.
... and he has a restraining order against him related to another individual.
Here is the only spot of possible trouble I can see.
IF he was a prohibited person at the time you gave the gun to him, that's an illegal transfer. If he did something really bad with it and you gave it to him knowing that he was not legally allowed to purchase or receive a gun, that could come back to bite you. If he was NOT prohibited at the time you gave it to him, any subsequent trouble he might have gotten into is not your problem.
What rights to i have to this gun...i never registered it or transferred it to him.
No rights whatsoever. There would have been no registration, because there ISN'T a registration of handguns in your state. You
DID transfer it to him, because giving it to him was a legal private transfer of ownership.
How do I legally go about getting the gun back?
I don't really see that you could. You gave it away as a gift. It belongs to him.
What process is there to use? Do I have a right to the handgun?
No. You have neither right to nor responsibility for that firearm.
I cannot transfer ownership, because of his restraining order,
If he has
become a prohibited person (i.e. a felon who cannot own or even touch guns), he can -- in fact MUST -- dispose of his firearms. So he certainly could transfer them to you. Now, a restraining order will stop him from legally being able to BUY a firearm, but it doesn't put him into the "prohibited" class of folks who may not OWN one. If he's not been convicted of a crime, he doesn't have to give up his guns (yet).
and even if I could, he has denied giving me the gun back.
You mean he's refused? Fine. It is his property and his responsibility. Your hands are clean.