Police say at least four people -- friends of Kennelly -- witnessed the fight, according to court documents obtained by ABC 7 News, and said Malecek delivered the fatal blow, described as a "sucker punch" to Kennelly's head.
He is charged with aggravated battery, involuntary manslaughter and battery.
"Investigation is ongoing. The Long Beach Police Department are still interviewing witnesses and trying to get statements, so we can now pin down as best we can as to what actually happened," said Robert Neary, LaPorte County, Ind., chief deputy prosecutor.
Police did not say what led to the attack, citing conflicting statements from people on the beach. However, according to some reports, a friend of Kennelly's insulted Malecek's sister, which led to the fight. Kennelly's father said that was all a misunderstanding.
"The only thing they can think is she had him confused with somebody else. There's hundreds of kids up and down the beach there in different groups. Maybe somebody else said something to her, and he happened to look like this kid. I don't know," Kevin Kennelly, Sr., said.
Kennelly Senior also disputes a 911 caller's account of the incident.
- Dispatcher: He's intoxicated, you said?
- Caller: Yeah, very much so.
- Dispatcher: Do you know who he is?
- Caller: No, I don't. Actually, I was just on the beach. And his friends are freaking out because he's underage, so nobody wanted to call.
Kennelly Senior is a trained paramedic. He says his son appeared sober when he saw his son less than hour before the fight.
"Would it have made any difference if they called five minutes earlier?" Kennelly Senior said. "I don't think so. The kid had massive brain trauma."
Malecek referred all questions to his attorney, who has not responded to multiple calls and emails from ABC 7. Malecek is free on a $25,000 bond. He will appear in court next on September 1.