As many of you have said there is no real defining moment.
My senior year of high school I was able to do ride-a-longs with the local PD, Sheriff's, and spend a day with the State Troopers and that opened my eyes up to all the bad in the world. Then I worked for the District Attorney (good friend of ours) and found out more about how evil people can be.
Around 5 years ago there was also a drug murder 1/2 from the house. I was able to see the pictures from it and it is alarming what a 12 ga. will do to someone's head.
Fast Forward to now: I have decided I want to be a New York State Trooper (I have to wait another 3 years to take the test) and I beleive in personal protection. I don't want to ever have to think to myself "I wish I had a firearm" and I like to always be prepared. Not only do I want to be able to protect myslef, but I want to be able to protect those around me.