There is no public access to the database the police use to track stolen firearms. You will have to call the police station and see if they will run a check over the phone, or take the weapon to them, or be fortunate enough to have a friend with access to the database.
"Laws that forbid the carrying of arms disarm only those who are neither inclined nor determined to commit crimes. Such laws make things worse for the assaulted and better for the assailants." - Thomas Jefferson, 1776