Sure. This murderer hasn't asked for forgiveness, nor has he repented his evil. Therefor forgiving him is a decidedly un-Christian thing to do.
That's incorrect. Here is the scripture.
Luke 23:34 - "Father, Forgive them for they know not what they do." - They had not repented...but Jesus was forgiving and was asking God's forgiveness for them.
Matthew 6:12 - "We forgive our debtors" - NO mention of their actions.
Matthew 18:21, 22 (para) - "How often shall I forgive...70x7"
Forgiveness is not about reconciliation between you and that person. Forgiveness is about you trusting God and understanding you have a debt to God that cannot be repaid. We have all broken God's divine laws and He by His grace has forgiven us. That GRACE being something we did not deserve, yet obtained. How can we deny forgiveness, grace, to fellow man, equally flawed?
Denying forgiveness, or offering forgiveness with conditions places you in the place of God...A place you are not meant to be. This is why Jesus said in Matthew 6:15 that if you do not Forgive men their sin against you (their repentence or lack thereof is not mentioned), you will not be forgiven. Why? Because, simply put, you are placing youself in the position of God as judge and jury.
Should each stand fast, or should one step forward...