I have a question regarding evil. Are people born evil or does life make them that way? I ask because I was reading this case of a serial killer in Ukraine who killed 52 people. How does someone become this twisted and not feel bad about it? I know it's not right to judge where a person's soul ends up, but where did this guy end up going?
Sin is always a choice. "Everyone who practices sin also practices lawlessness; and sin is lawlessness" (I John 3:4). Therefore, it is neither due to birth nor environment, though environment might encourage a person to make wrong choices.
Any sin that is repeated often enough causes a person to become numb to the guilt of sin. "So this I say, and affirm together with the Lord, that you walk no longer just as the Gentiles also walk, in the futility of their mind, being darkened in their understanding, excluded from the life of God because of the ignorance that is in them, because of the hardness of their heart; and they, having become callous, have given themselves over to sensuality for the practice of every kind of impurity with greediness" (Ephesians 4:17-19).
I can't say where this person ended up because I can't tell you how his life ended. But we do know that unrepentant murders end up in hell. "But for the cowardly and unbelieving and abominable and murderers and immoral persons and sorcerers and idolaters and all liars, their part will be in the lake that burns with fire and brimstone, which is the second death" (Revelation 21:8).