Let's take a look at verses of Exodus 2:11-14 (also see my NIP here for SP and DSS variants, very interesting ones too):
11 וַיְהִ֣י׀ בַּיָּמִ֣ים הָהֵ֗ם וַיִּגְדַּ֤ל מֹשֶׁה֙ וַיֵּצֵ֣א אֶל־אֶחָ֔יו וַיַּ֖רְא בְּסִבְלֹתָ֑ם וַיַּרְא֙ אִ֣ישׁ מִצְרִ֔י מַכֶּ֥ה אִישׁ־עִבְרִ֖י מֵאֶחָֽיו׃12 וַיִּ֤פֶן כֹּה֙ וָכֹ֔ה וַיַּ֖רְא כִּ֣י אֵ֣ין אִ֑ישׁ וַיַּךְ֙ אֶת־הַמִּצְרִ֔י וַֽיִּטְמְנֵ֖הוּ בַּחֽוֹל׃13 וַיֵּצֵא֙ בַּיּ֣וֹם הַשֵּׁנִ֔י וְהִנֵּ֛ה שְׁנֵֽי־אֲנָשִׁ֥ים עִבְרִ֖ים נִצִּ֑ים וַיֹּ֙אמֶר֙ לָֽרָשָׁ֔ע לָ֥מָּה תַכֶּ֖ה רֵעֶֽךָ׃14 וַ֠יֹּאמֶר מִ֣י שָֽׂמְךָ֞ לְאִ֨ישׁ שַׂ֤ר וְשֹׁפֵט֙ עָלֵ֔ינוּ הַלְהָרְגֵ֙נִי֙ אַתָּ֣ה אֹמֵ֔ר כַּאֲשֶׁ֥ר הָרַ֖גְתָּ אֶת־הַמִּצְרִ֑י וַיִּירָ֤א מֹשֶׁה֙ וַיֹּאמַ֔ר אָכֵ֖ן נוֹדַ֥ע הַדָּבָֽר׃
11 And it came to pass in those days, when Moses was grown, that he went out unto his brethren, and looked on their burdens: and he spied an Egyptian smiting an Hebrew, one of his brethren.12 And he looked this way and that way, and when he saw that there was no man, he slew the Egyptian, and hid him in the sand.13 And when he went out the second day, behold, two men of the Hebrews strove together: and he said to him that did the wrong, Wherefore smitest thou thy fellow?14 And he said, Who made thee a prince and a judge over us? intendest thou to kill me, as thou killedst the Egyptian? And Moses feared, and said, Surely this thing is known.
So was Moses a murderer? As far as I can tell - only by proxy at best. As you can see KJV translation above in verse 12 says "slew" but in reality the Hebrew text says "smite". Thus, it seems that Moses most likely "knocked out" the Egyptian and "hid or "burried him in the sand" (for God to decide his fate). As we well know from the following verses, Egyptian died, but not because of Moses but because of the sand. He was still alive before he was "hid" or "buried".
What do you think?