Life is a gift from God. Every human being is created by God in His own Image and Likeness. When a person commits sin by performing brutal actions or unjust aggression, that person tarnishes the Image of God. In His goodness, God calls that person to repentance. Repentance leads to conversion.
Conversion is a lifelong process that effects reconciliation.
To execute Mark Fowler is to cut short the penance and conversion he needs to make. To execute Mark Fowler does not bring back the lives of those he is accused of killing. To execute Mark Fowler does not effect a single positive objective fact. To execute Mark Fowler does not rectify the wrong that he did. Executing Mark Fowler only perpetuates the violence and evil he perpetrated.