Answer:
Depending on how you interpret scripture and whether you prefer to put more emphasis on New or Old Testament law, you can argue a case for capital punishment or against. Take for instance Matthew 5:38-39 Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth: But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also.
Some use this to say Old Testament law was for capital punishment, New Testament teaching against it. However this verse is sometimes taken out of context as demonstrated in the commentary notes below:
Matt 5:38 Verses 38-41. An eye for an eye, etc. This command is found in Ex 21:24; Le 24:20; De 19:21. In these places it was given as a rule to regulate the decisions of judges. They were to take eye for eye, and tooth for tooth, and to inflict burning for a burning. As a judicial rule it is not unjust. Christ finds no fault with the rule as applied to magistrates, and does not take upon himself to repeal it. But, instead of confining it to magistrates, the Jews had extended it to private conduct, and made it the rule by which to take revenge. They considered themselves justified, by this rule, to inflict the same injury on others that they had received. Against this our Savior remonstrates. He declares that the law had no reference to private revenge; that it was given only to regulate the magistrate; and that their private conduct was to be regulated by different principles. The general principle which he laid down was, that we are not to resist evil; that is, as it is in the Greek, not to set ourselves against an evil person who is injuring us. But even this general direction is not to be pressed too strictly. Christ did not intend to teach that we are to see our families murdered, or to be murdered ourselves, rather than to make resistance. The law of nature, and all laws, human and Divine, have justified self-defense, when life is in danger. It cannot surely be the intention to teach that a father should sit by coolly, and see his family butchered by savages, and not be allowed to defend them
So, to summarize, all sins can be forgiven of God and the murderer, etc can still enter into Heaven if their hearts are truly repentant and they seek God’s mercy. It does not mean that consequences of their actions will not be dealt with here on earth. If you take the Bible literally, as I do, then all indications would be that for certain offenses capital punishment would be the consequences of certain actions here on earth, even though the sin itself might be forgiven by God (under the right heart circumstances).
Does this help?
Pastor Brad