His blood is permitted
It is permitted to kill him; his life is no longer regarded as having value.
("He is a rebel in the kingdom and considered as dead, and now... as if he is dead, and his blood is permitted and his wife is permitted" - Bereishit Rabba (Vilna edition) Parashat Noach, Section 32, and similarly: "Therefore, one who enters a cellar if he breaks a barrel at the time of his entry and there were no witnesses, his blood is permitted" - Commentary on the Mishnah by Maimonides, Tractate Sanhedrin 8.)
Translation
Expression (Hebrew)
דָּמוֹ מֻתָּר
Definition (Hebrew)
מֻתָּר לְהָרְגוֹ. חַיָּיו אֵינָם נֶחֱשָׁבִים יוֹתֵר כְּבַעֲלֵי עֵרֶךְ.
("מוֹרֵד בַּמַּלְכוּת הוּא וְחָשׁוּב כְּמֵת, וְעַכְשָׁו... וְכָאֵלּוּ הוּא מֵת וְדָמוֹ מֻתָּר וְאִשְׁתּוֹ מֻתֶּרֶת"- בְּרֵאשִׁית רַבָּה (וִילְנָא) פָּרָשַׁת נֹחַ פָּרָשָׁה לֵב, וְכֵן:"וּלְפִיכָךְ הַבָּא בַּמַּחְתֶּרֶת אִם שָׁבַר חָבִית בִּשְׁעַת כְּנִיסָתוֹ וְלֹא הָיוּ שָׁם עֵדִים שֶׁדָּמוֹ מֻתָּר"- פֵּרוּשׁ הַמִּשְׁנָה לָרַמְבָּ"ם מַסֶּכֶת סַנְהֶדְרִין ח ו)