In the Old Testament, the following acts were to be punished by death:-
Deliberate homicide (Exod 21:12-14, Lev 24:17). One witness was insufficient (Num 35:30).
Attacking or cursing a parent (Exod 21:15, 17, Lev 20:9), or refusing to obey a parent when being disciplined for being profligate and a drunkard (Deut 21:18-21).
Kidnap (Exod 21:16).
Being a sorceress or medium or spiritist (Exod 22:18, Lev 20:27).
Having sex with an animal (Exod 22:19, Lev 20:15-16).
Sacrificing to any god other than the Lord (Exod 22:20).
Working on the Sabbath day (Exod 31:14-15, 35:2).
Giving children to Molech by passing them through the fire (Lev 20:2).
Adulterer and adulteress (Lev 20:10-12).
Sleeping with your father's wife or daughter-in-law (Lev 20:11-12).
A man sleeping with a man (Lev 20:13).
A man marrying both a woman and her mother (Lev 20:14).
Cursing the Lord and blaspheming his name (Lev 24:16).
Non-Levites disassembling the tabernacle (Num 1:51).
Non-High Priests approaching the sanctuary (Num 3:38, 18:7).
A prophet instructing people to follow another God, and a town that accepts his message (Deut 13:1-18, 17:2-7); also a prophet who presumes to speak in God's name anything God has not commanded him to say (Deut 18:20).
A man showing contempt for judge or priest ministering to the Lord (Deut 17:12).
Female promiscuity before marriage (Deut 22:21).
-oOo-
Although we don't have the death penalty for crimes in the UK today, I observe a lot of death being inflicted on innocent people, such as in the abortion industry, and through climate change. A billion people live within one metre of sea level; sea levels are rising a millimetre every two months and we are doing little to turn this around. This seems unfair to me. Locally, eighteen million people in Holland will need to be re-housed with just half a metre of sea level rise, if they don't die when the dykes give way. It seems, then, that we have replaced one form of the death penalty with another, only this time, it will be the innocent who die.
If you feel condemned by the above list, the New Testament explains how guilt can be dealt with. We have all sinned and fallen short of God's glory (Rom 3:23), but if we confess our sins, God forgives us and the blood of Jesus purifies us from all unrighteousness. God will give his Holy Spirit to evil people who ask him (Luke 11:13), and the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness and self control (Gal 5:22-23).