non est inventus

from The Collaborative International Dictionary of English v.0.48

Non est inventus \Non` est` in*ven"tus\ [L., he is not found.]
   (Law)
   The return of a sheriff on a writ, when the defendant is not
   found in his county. --Bouvier.
   [1913 Webster]

from Bouvier's Law Dictionary, Revised 6th Ed (1856)

NON EST INVENTUS, practice. The sheriff's return to a writ requiring him to 
arrest the person of the defendant, which signifies that he is not to be 
found within his jurisdiction. The return is usually abbreviated N. E. I. 
Chit. Pr. Index, L. t.

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