Article 4, Section 2, Clause 2
Joseph Story, Commentaries on the Constitution 3:§§ 1802--31833
§ 1802. It has been often made a question, how far any nation is, by the law of nations, and independent of any treaty stipulations, bound to surrender upon demand fugitives from justice, who, having committed crimes in another country, have fled thither for shelter. Mr. Chancellor Kent considers it clear upon principle, as well as authority, that every state is bound to deny an asylum to criminals, and, upon application and due examination of the case, to surrender the fugitive to the foreign state, where the crime has been committed. Other distinguished judges and jurists have entertained a different opinion. It is not uncommon for treaties to contain mutual stipulations for the surrender of criminals; and the United States have sometimes been a party to such an arrangement.
§ 1803. But, however the point may be, as to foreign nations, it cannot be questioned, that it is of vital importance to the public administration of criminal justice, and the security of the respective states, that criminals, who have committed crimes therein, should not find an asylum in other states; but should be surrendered up for trial and punishment. It is a power most salutary in its general operation, by discouraging crimes, and cutting off the chances of escape from punishment. It will promote harmony and good feelings among the states; and it will increase the general sense of the blessings of the national government. It will, moreover, give strength to a great moral duty, which neighbouring states especially owe to each other, by elevating the policy of the mutual suppression of crimes into a legal obligation. Hitherto it has proved as useful in practice, as it is unexceptionable in its character.
Story, Joseph. Commentaries on the Constitution of the United States. 3 vols. Boston, 1833.