It is forbidden for the court to have compassion for the killer. The judges should not say: "Since this person has already been killed, what advantage is there in killing another person," and thus be lax in executing him. This is implied by Deuteronomy 19:13: "Do not allow your eyes to take pity. You shall eliminate innocent bloodshed."
Similarly, it is forbidden for the court to take pity on a person who was obligated to pay a fine. They should not say: "He is poor. He acted unintentionally." Instead, they should exact the entire payment from him without compassion, as Ibid.:21 states: "You shall not take pity."
Similarly, in questions of monetary law, one should not show mercy to the poor, saying: "He is indigent and the other litigant is wealthy. Since both I and the wealthy man are obligated to provide for the poor person's livelihood, I will vindicate him in judgment and thus he will derive his livelihood with honor." With regard to this, the Torah warned Exodus 23:3: "Do not glorify the indigent in his dispute," and Leviticus 19:15: "Do not show favor to the poor."
It is forbidden to show favor to a person of stature. What is implied? Two people come before one for judgment, one a wise man of stature and one, an ordinary person. One may not ask about the welfare of the person of stature first, nor treat him with favor, nor show him honor, lest this cause the other litigant to become tongue-tied. Instead, the judge should not turn to either of them in a personal manner until the judgment is concluded. This is derived from [Ibid.: "Do not glorify the countenance of a person of stature." Our Sages said: One should not say: "This man is affluent; he is the son of people of stature, how can I embarrass him and witness his humiliation." With regard to this, it is written: "Do not glorify the countenance of a person of stature."