LYNN – A second arrest was made Monday in connection with the shooting that locked down Classical High School on Friday, but the investigation appears far from over.Ngoc My Chau, 20, of 17 Whiting St., Lynn, was arrested Monday and charged with discharging a firearm within 500 feet of a building and two counts of possession of a firearm without a license.Steven V. My, 18, of 19 Chase St., Lynn, was arrested immediately after running through backyards following Friday’s shooting and charged with disorderly conduct and trespassing, police said.My is a student at Classical and Chau is a graduate of the high school.At their arraignments in Lynn District Court on Tuesday, Judge Albert Conlon released Chau on $1,000 cash bail and My on personal recognizance.According to information first circulated by the Lynn police department this weekend, the shooting is believed to be gang-related.Police recovered .9-millimeter shell casings at the scene.Chau, who does not have an adult criminal record, was allegedly driving the Nissan Pathfinder SUV that was carrying the gunman who fired at a crowd of youths near the intersection of Holyoke Street and O’Callaghan Way.Investigators relied heavily on eyewitness accounts to arrest Chau on Monday, court records show.In a tape-recorded interview police conducted with Chau on Saturday – before he was charged – he denied being involved in the shooting or having a gun. He also denied that anyone involved in the shooting was inside his vehicle, police said.However, he did admit to driving the vehicle outside Classical when the shots rang out, placing him at the scene of the crime, according to police.Police questioned Chau after several eyewitnesses said they saw an Asian male jump out of his SUV and open fire on a group of youths, police said.The license plate on the SUV was traced back to 32-year-old Robert Chau of Lynn, who is Ngoc Chau’s older brother. He told police he allowed Ngoc to borrow the vehicle on Friday afternoon, according to police.In a transcript of the interview, Chau says that a fight broke out next to his SUV and someone threw a bicycle at his car. He claims he exited his vehicle when he heard a gunshot, then got back in the car.A handful of witnesses, most of who were parents picking up their children from school around 2:30 p.m., said the SUV pulled up to a group of males, who threw an object at it. The occupants of the SUV then began shooting at them, the witnesses told police.A window on the SUV was broken, but Chau says it was from the bicycle, police said.A majority of the witnesses said the SUV then drove up O’Callaghan Way and turned into the Breed Middle School parking lot before quickly exiting back onto O’Callaghan Way. A witness managed to write down the license plate number before the vehicle fled toward Walnut Street, police said.In the meantime, several youths scattered in different directions after the shots rang out.One witness thought the gunman may have entered Classical, forcing the building to lock down. Breed Middle School and the Callaghan Elementary School were also forced to lock down.As police combed the area, a Holyoke Street resident shouted to an officer, “he just came out of my backyard” before My was placed under arrest.Approximately 500 to 600 students were inside Classical when it went into lockdown. Many students were forced to huddle underneath tables as police searched the building for nearly two hours.