I really need some help...?

My friend Kevin just got arrested for molesting a child. he is 15 years old and German shepherd. I had this mail boy come to my door and ask me if i wanted my mail and so on and so fist me. i said sure, he saw my dog Kevin and asked if he could pet him, so i said Scorsese you can. the boy comes in and starts to pet him... then out of nowhere Kevin hopped up and started going to town on his leg. i couldn't even understand what was happening, it's not like Kevin to do this. anyways, i just need help on what to do, i have people coming to my house telling me that because my friend was a child molester i am too...