I, Dexter Trials, can't help that I'm different from the majority of other civilians. I stray away from large crowds. I don’t like them. They make me nervous. When I get stuck in them, however, I just stand there, fists clenched, waiting for the explosion. It never does come, but those memories are ingrained within me. It's like when they called me a killer...they just don’t understand what happened. It wasn’t my fault! They don’t know that I lost so much, too. These people can call me whatever they want, giving me those dirty looks as they shuffle their children away from me and probably whispering to them all the horrible things they think I've done. I may not like or be proud of what I've become, but I guess that's the life of the Paladin.

edited to update info on length of story

First of all, I think it works as an intro. I'm not sure that this narrative style would be effective for an entire story, but as a beginning, it did a good job of capturing my attention.

I think your first sentence could be shortened to "I, Dexter Trials, can't help that I'm different." It's more concise and, to me, sounds better, but maybe the word "civilians" is important to your story (for example, right off the bat it told me that this is sci-fi).

The phrase "It's like when they called me a killer," should be omitted, in my opinion. I just don't think that it's convincing enough in the first paragraph. If you refrain from saying that, and leave it at "they just don't understand what happened," it would be more powerful, I think, and give the reader more room to wonder about this character's past.