I can understand the feelings of vengeance and hate, but they are counterproductive to the personal self.
I have, thankfully never had a relative or close friend murdered 'though did have an uncle killed by ‘German’ action during WWII], but my parents-in-law did something pretty much as bad, and indeed that also had very protracted outcomes.
Yes, I know what it is like to ‘hate’ someone, but found it to grind at my own ‘inner man’ - when I decided to ‘let go’, and indeed pray for those who had caused so much damage, I actually felt release.
I recalled, ‘forgive us our trespasses AS WE FORGIVE THEM THEIR TRESPASSES AGAINST US’, and was also reminded of Jesus on the cross, and what He did and continues to do for me.
'Feel free to hate the sin, but ‘love’ the sinner, who is to all intents and purposes also ‘your neighbour’…
I was a teenager when the UK still had the death penalty, and felt a certain hypocrisy in the judge’s words that that both condemned the person to die and wished God to grant clemency to the soul.
ps. Finding the ‘guilty person’ even now can be a bit of an imperfect science, it is a little late to say, oops, sorry, after an innocent person has been judicially ‘topped’.
While Jesus never in as many words repudiated capital punishment, He did by His own actions questions and statements seemed to prefer forgiveness and clemency.
In Shakespeare’s words:
The quality of mercy is not strained;
It droppeth as the gentle rain from heaven
Upon the place beneath. It is twice blest;
It blesseth him that gives and him that takes:
‘T is mightiest in the mightiest; it becomes
The throned monarch better than his crown:
His sceptre shows the force of temporal power,
The attribute to awe and majesty,
Wherein doth sit the dread and fear of kings;
But mercy is above this sceptred sway;
It is enthronèd in the hearts of kings,
It is an attribute to God himself;
And earthly power doth then show likest God’s
When mercy seasons justice.