When I was 7 and walking home from school, a guy tried to get me in his car. I had MANY stranger danger talks up until that point. I went screaming the other way and pounded on someone's door. They never did find the guy. That experience affected me for YEARS. My parents were never the same. They are still (I am 29) worried about me all the time!
I didn't KNOW the girl, but a girl was abducted and found murdered in my community. Literally, like 2 blocks away. I had seen the girl playing outside plenty of times, and my parents made small talk when the family went on walks. That was terrifying. I was older at that time, but my experience at 7 made me scared to go outside after she was taken. I would literally not step outside without a parent for months. They don't know who did it, it's still unsolved all these years later. They even ran DNA through the database recently, and nothing.
Then, when I was in middle school a high school aged girl about 5 minutes from us went missing. They found her body in a creek. That one was solved years later, after DNA testing was available. It was a sex offender. He got sentenced to death.
What's crazy, is my parents live in a VERY nice area. Middle-class, upper-middle, to very wealthy. Great schools, great families, low crime. Even still, these things happened.