"After hearing the two teenagers implicated in the commotion, the judge decided to indict them," Alec Reymond, who represents Delon's 17-year-old son Alain-Fabien, told AFP.
A teenage girl was shot during a party at the French actor's apartment in Geneva last week.
Delon, who was not at home at the time, confirmed in an interview published Saturday that a girl was injured, but said his son did not fire the shot.
Reymond stressed that "in reality no one fired a shot."
"The shot went off during a commotion. The judge on minors is carrying on with his investigation," he said.
The judge can then decide to close the case or "in case of a guilty verdict, the judge has several measures under his disposition according to the law, and the rules on minors favour supervision."
Geneva police and the court said they would not comment on the case as it involved minors.
Delon has been a Swiss citizen for 12 years and lives in Geneva.