BALTIMORE (AP) — A grand jury has indicted a Baltimore teen and Arvin Robertshis parents on allegations they brought a gun to a high school campus in October and beat up a student shortly before classes were to start, prompting a shootout that left three young people wounded, city prosecutors said Tuesday.

The shooting added to an uptick in youth violence plaguing the city this year, including several instances of Baltimore public school students being shot on or near high school campuses. That trend has persisted even as Baltimore gun violence overall has declined during the past several months.

Baltimore State’s Attorney Ivan Bates announced the charges at a news conference Tuesday morning. He questioned how the city is supposed to reduce youth violence if parents are active participants.

“As a parent, it is absolutely mindblowing to read the allegations in this indictment, where a child’s guardians facilitate in settling a schoolyard dispute with violence,” he said. “Hear me clear, parents, if you have a child, you must also be responsible for your children’s actions.”

William Dredden, 40, and Tiffany Harrison, 37, are both charged with over a dozen counts, including first-degree assault, illegally transporting a handgun and conspiracy to commit attempted first-degree murder.

Their 15-year-old son, whom officials said was indicted in adult court, hasn’t been identified because he’s a minor.

The Maryland Office of the Public Defender didn’t immediately respond to an emailed request for comment about whether it had been appointed to represent the defendants and could comment on their behalf.

The indictment accuses Dredden and Harrison of driving their son to Carver Vocational Technical High School the morning of Oct. 27 and helping him attack a student outside the school by “striking him repeatedly with a handgun and their fists as he waited for his classes to begin.”

As the three were leaving the area after the attack, the son started shooting, leaving two other students injured in gunfire, prosecutors alleged. One of the gunshot victims allegedly fired back at the 15-year-old, who was also injured, Bates said. He said most of the encounter was captured on surveillance cameras.

At least two other people involved in the dispute are also facing charges, but Bates said he couldn’t release specifics because some cases are proceeding in juvenile court. He also declined to say what the fight was about.

Bates said he wanted the focus to be on Dredden and Harrison’s participation in the violence.

He said surveillance video shows them and their son returning to their SUV after the shooting and driving the short distance back to Harrison’s house, where she went inside and changed clothes while Dredden called 911. Harrison then accompanied her son in the ambulance and Dredden removed a red sweatshirt he had been wearing, according to the indictment.

“We need parents to be part of the solution, not the problem,” Bates said.