Is it legitimate for a jury to find a defendant guilty of manslaughter in a case where there is evidence of premeditation, simply because members of the jury feel that the defendant was somewhat justified in taking the life of the victim?

Is it legitimate for a jury to find a defendant guilty of manslaughter in a case where there is evidence of premeditation, simply because members of the jury feel that the defendant was somewhat justified in taking the life of the victim?

Please post your reply to the above question of at least 150 words.