Ali Cross Like Father, Like Son (Ali Cross 02) by James Patterson

The story opens with Ali and his friends, Gabe, Sedgwick, Ruby, Matteo, and Zoey sneaking off to attend a music festival at a Washington DC park. Ali is strictly forbidden to go to this area alone, but, like many teens, he is pushing his restrictions to get his parents to look at him as older. Besides, he is crushing on Zoey, and does not want to appear wimpy in front of his friends.
After the group hit the food booths, Zoey runs off to get the venue passes from her mother, one of the singers. Within minutes, the kids hear a gunshot. They run to check on Zoey who is hurt. Ali believes he sees the shooter running away, but Zoey insists there wasn’t anyone near her. The police are called, Zoey is taken to the hospital, the kids get in trouble, Nana mama and Alex Cross ground Ali for life, (not really but he gets a long punishment without technology). Ali and friends are determined to find out what happened and why Zoey is so nervous.