Pawning Somebody Else's Property

My question involves criminal law for the state of: texas

I pawned a item that was not mine but was not stolen.

So how did you come into possession of it?

If you lawfully gain possession of somebody else's property, but then treat the property as if it is your own in defiance of the actual owner's property rights (such as by pawning or selling it), that's likely going to be regarded as theft by conversion. Texas has consolidated its theft offenses, so it's likely to be prosecuted as theft even if you feel that your actions did not involve "stealing" the property that you pawned.

If you have not yet been charged, redeem the property and return it to its owner. If you have been charged, consult a criminal defense lawyer with the facts.