Catholics are Christians as in they follow and believe in Yeshua.
and religious people often are motivated by their religion and interpretation of the bible passages to commit crimes of violence like abortion bombing and gay bashing.
how often have we heard fanatics scream homosexuality is an abomination against God and should be killed?
Also the old testament pretty much tells you it is okay to kill others that do not follow God's laws or do not believe in him.
Deuteronomy 17
If there be found among you, within any of thy gates which the LORD thy God giveth thee, man or woman, that hath wrought wickedness in the sight of the LORD thy God, in transgressing his covenant; 17:3 And hath gone and served other gods, and worshipped them, either the sun, or moon, or any of the host of heaven, which I have not commanded; 17:4 And it be told thee, and thou hast heard of it, and enquired diligently, and, behold, it be true, and the thing certain, that such abomination is wrought in Israel; 17:5 Then shalt thou bring forth that man or that woman, which have committed that wicked thing, unto thy gates, even that man or that woman, and shalt stone them with stones, till they die.