The incident happened Saturday night at Great Adventure's FestEVIL, featuring the heavy metal band Falling in Reverse.
At the end of the show lead singer Ronnie Radke can be seen in a home video throwing three heavy microphone stands into the screaming crowd.
One of them left a bloody gash in 24-year-old Phillip Schwartz's head that required 3 staples to close the wound.
"I went to touch it and I felt my finger go into the wound and I said 'there's a dent in my head. There's a dent in my head,'" Schwartz said.
Police say the flying mic stands also clobbered a teenage girl from Egg Harbor Township.
"The 16-year-old female suffered a 3 inch laceration to her scalp which required staples to close. She was also diagnosed with a concussion," Jackson Township Police Captain John Siedler said.
A police officer on duty at the concert witnessed what happened and arrested Ronnie Radke in his dressing room after the show on aggravated assault charges.
Nursing his wounds, Phillp Schwartz of Garwood sent a message to the singer on Instagram saying, "I know you didn't mean to intentionally hurt anyone on Saturday but unfortunately you did."
Radke offered no apologies, but asked for Schwartz's Twitter address.
Great Adventure has worked hard over the years to brand itself a family park. This is the first time a metal band has ever appeared here and officials say it will be the last. In a statement to Action News, Six Flags officials said:
Six Flags aims to provide diverse entertainment that reflects the varied interests of our guests, while providing a safe, family environment. This was the park's first metal show, and was a private event open only to special ticket holders. The performer's actions were reckless, unacceptable and a complete disregard for the safety of his fans. The safety of our guests and employees is our top priority.."
Radke was released on $25,000 bail.
The California resident will have to come back to New Jersey for return engagement-this time in a courtroom.