On feeling sympathy for truly lost people

In light of the Boston Marathon bombings and the hunt for the two perpetrators, I've been spending a lot of time on news sites. I generally find cases like these interesting, since I'm curious as to what makes people do the things they do, especially when they're seriously violent. Anywho, for all you who have been living under a rock lately, the bombings were carried out by two brothers, Dzhokhar and Tamerlan Tsarnaev. Now from what I've gathered from news coverage, it seems like Dzhokar, the younger brother, was a pretty smart and well-adjusted kid with a promising athletic future, living with his older brother Tamerlan, who'd apparently had some run-ins with the law (like for beating his girlfriend) and was generally a pretty shady character who didn't fit in. Their father (or uncle? I can't remember) has apparently said in the media that Tamerlan was a bad influence on his little brother, and I don't know if it's because of the younger brother's age or whatever, but I feel for the kid. I really do.
I know that sounds pretty fucked up - he killed four people, including an 8-year old, by detonating bombs at a packed place filled with hundreds of people. A good number of the 180 or so wounded lost limbs, and life probably won't be the same for any of those present. I don't know why I feel genuinely sorry for him. I try imagining myself in his position - living together with a brother he looks up to, who's set on doing some crazy shit for a cause he strongly believes in. It would be hard not to get pulled in with the rhetoric, eventually coming to share the angry beliefs of someone with a problem adjusting to the American lifestyle. Somehow I want to think that Dzhokar Tsarnaev's heart wasn't in it, probably because he visually reminds me so much of a younger student in my school who I'll call the Puppy (because he reminded me so much of a puppy when I first got to know him because of all his excess energy I was scared he was going to pee on the carpet out of excitement), whom I've taken under my wing a bit. They're both born the same year and share the same unruly kind of hair, and it's impossible for me to picture so much malice as it must've taken to do such a horrible thing coming from someone like the Puppy. 19-year old boys aren't supposed to want to blow people up. Clearly, neither are 26-year olds, but somehow it's worse when they're younger. I know me at 19 - I was insecure and scared and all those things. If my brother (whom I hero-worshiped as a kid) would've, for any reason, decided that he wanted to detonate a bomb for some political reason, I wouldn't know what to do. Obviously try to stop him, but the thought of turning him over to the police feels terrible.

I feel like someone's grandma when I say that I get sad when young people commit crimes or do stupid shit that will fuck their lives up for no good reason. I don't know what they thought they would accomplish - they'd obviously get caught, but the thought of what it must feel like hiding in a boat on land, bleeding heavily, while 9 000 police officers look for you and the entire country wants you dead must feel like the loneliest thing on the planet. I'd like to think that he wouldn't have done it if he could've done it all over again at that point in time. Obviously these feelings of sympathy for the perpetrator in no way overshadow the feelings for his victims, just that the whole thing's a tragedy. Imagining the Puppy taking the wrong turn, getting in with the wrong crowd, detonating a bomb, being chased and hated by everyone in the entire country, getting shot, bleeding out in a boat on land and not being able to take it all back - it breaks my heart.