Elder was charged in 2016 with an attack by a classmate who, according to a source with knowledge of the events after the incident, was seriously injured.
Elder, then 16 years old, beat a fellow student and football teammate from San Francisco's Sacred Heart Preparatory School, causing the victim to bang his head on the sidewalk, CNN said. It is not clear what penalty Elder may have received.
The San Francisco Procuratorate did not comment on the case because it was a minor and the juvenile files were sealed. The San Francisco police did not comment immediately.
"Plunged into Coma"
The Chronicle reported that Elder at night hired a member of his high school football team to gather students.
Caleb Lagafua, who was in the football team with Elder at the time, told CNN that he was absent that night. But he remembered the consequences of the incident.
"I remember the kid he hit … was put into a coma … and then have the parents I think the boy did not come back until the last school months, "he said.
Lagafua, now attending college in San Francisco, said Elder told him about the incident later.
"I remember Finn trying to tell me the whole story, he told me it was not his first contact. He said after he hit him, he fell and hit his head on the rock . "
Lagafua said he was friends with Elder, but tried to stay away from his team-mate. He remembers Elder arguing with his team-mates during football practice. "It was stupid stuff," Lagafua said.
"He was always running around with some bad kids and I did not want to mess up my future, but I remember the fight because it happened over a longer period of time." I remember coming back to school over the weekend and everyone was talking about Finn being in jail … it was crazy because I did not think that something like that would happen to Sacred Heart's anger in him.
published a news release, citing a San Francisco police spokeswoman, reporting that the victim was hospitalized with "life-threatening injuries" and that El The Elder family had no immediate comment, but the spokesman for the family and uncle Sean Elder of Finnegan Elder told the Chronicle that the incident in 2016 was part of a Reciprocity was a pre-arranged fight that many members of the football team knew about and that they pushed on. "
" I've known Finn all his life and have never seen him violent or even lose control, "said Sean Elder Chronicle.
He added that Finnegan did not receive any disciplinary action from the school.
US citizens Elder and Gabriel Natale Hjorth, 18, were arrested last Friday in their room at the Roman hotel Le Méridien Visconti, accused by the Italian police that day Carabinieri officer, Mario Cerciello Rega, killed.
Rega, who was unarmed and in civilian clothes, was assaulted while attempting to retrieve a backpack that was allegedly stolen by Elder and Hjorth after a botched drug deal
While both teens were reportedly attacking the police, Elder is accused of stinging Rega eleven times with a 7-inch knife, officers say He brought them from the USA to Italy.