Worried and Sad

I wonder what things are coming to anymore, we live in a very small town, the next town over is bigger (Lowe's, fast food restaurants etc) but still small. Anyway we had a scare last week, my daughter was at the park, with friends (next town over) and these kids jumped out of their car and started beating up this older man. My daughter ran across the park screaming at them and waving her hands, as she got to them they jumped into their car and drove away. My daughter called 911 and held him on his side (he was chocking on blood) and waited for the ambulance. When the EMT'S got there one of them walked her to the ambulance and sprayed her down (she had blood on her arms and pants). Me being Mom was scared when she got home so I called the police and ask if the gentleman was okay and could I find out if he any blood disease's? I have not heard back yet but the police said if the person doesn't want to divulge any information there is no way for me to know. Her Doctor (small town) knows us well and did a blood work up on her and tests came back fine, this gives us a good base now she has to have another one in 6 months before we know if everything is ok. I understand his rights and freedom, but this is a 17 year old kid and he is 70 if he just would say he didn't have anything....I would still do the tests, but it would put our minds to rest (a little) while waiting! Now I have to wait 6 months and worry, she didn't have any visible cuts on her arms (The EMT checked and I did also) so that is good! I would never tell one of my kids to not help now or in the future in fact I have always said help if someone is in need but I have also always said be very careful if blood is involved. My daughter was just not thinking at the time (about being careful with blood) she just wanted to help him she said she didn't notice the blood on her until the ambulance got there.  I just don't understand what kids (and adults) are thinking anymore why beat up an elderly person? What do they gain from hurting other people, they apparently didn't even know the gentleman, one of the kids was just mad about something else (he told the police) and took it out on the first person that came along. Keep us in your prayers that her tests in 6 months come back okay.