"Cases of rape and murder could be quelled substantially through better economic opportunities and greater access to healthcare, including abortions. Bad men usually had bad upbringings."
This isn't necessarily the case. There are plenty of rapists and murderers that came from a good home. It's hard to say why some people do bad things.
Bad upbringing is usually caused by bad parenting. You can't force a parent to spend time with their child or be there for them.
Some people also just shouldn't be parents. They pass on terrible traits that result in criminals.
"We probably can do better as a species, but we need to address all of the issues of the human condition with compassion, research, and empathy, not with guns and cages."
You make it sound so simple. We will always need guns and cages because no matter how much health care and good upbringing a person has, there will still be criminals.
Look at Norway as an example. Everyone has free health care, easy access to abortions, and the unemployment rate is ~3%. Prisoners are treated very well there and the prison systems are some of the best in the world (if I was a criminal, I would probably move to Norway). Here is an article about it:
http://www.dailymail.co.uk/home/moslive/article-1384308/Norw...
By taking away "guns and cages" you will only hurt the honest people in this world. They are there for our protection and no amount of compassion or empathy will prevent our need for them.