Having reached Chapter XLIV in Gibbon, which deals with the origin and development of Roman law, I decided to check out the Twelve Tables on the net. In Law IV, Note 1, 2nd paragraph, I find the following:
As stated above, to render the modicide justifiable, the Visigoths required that the thief should be in possession of the stolen property; and the Castilian law provided that he should be armed and resist arrest while in the house of the owner.
OED comes up empty on the word modicide, which I can only assume is the killing of a thief. I’m intrigued by the root though. The nearest term to it in OED is modicity, a rare word for moderateness, from the Latin modicus, moderate. Clearly this does not fit the bill. Any suggestions?