LYNN – Another Lynn youth was arrested Thursday in connection with a shooting that sent Lynn Classical High School into lockdown exactly one week ago today.Giang Tran, 17, of 105 Ashland St., was arrested at about 10:30 a.m. and charged with discharging a firearm within 500 feet of a building, unlawful possession of a firearm and ammunition and participating in an affray.Tran is a Classical student and was arrested at the school, according to Police Capt. Mark O’Toole.Further details of the arrest were not released Thursday. Tran is expected for arraignment in Lynn District Court today.His arrest comes one day after Lynn police arrested Many Keo, 19, on similar charges after two eyewitnesses identified him as the shooter in a photo line-up. But as Keo was being arraigned, police were able to confirm his alibi that he was working when the shooting occurred at approximately 2:30 p.m. last Friday.Ngoc My Chau, 20, of 17 Whiting St., was arrested Monday after he admitted to driving the SUV that police believe was involved in the incident.Steven V. My, 18, of 19 Chase St., was arrested within minutes after shots were fired when he was seen running through backyards. He was only charged with trespassing and disorderly conduct.My is a Classical student and Chau is a graduate.Several witnesses, including parents and teachers, told police that a Nissan Pathfinder stopped near the corner of Holyoke Street and O’Callaghan Way around dismissal time last Friday when a confrontation brewed outside the vehicle. Someone allegedly threw a bicycle at the SUV when suddenly a young man pulled out a gun and fired.The shooting caused chaos as dozens of people ran in different directions and three nearby schools – Classical High, Breed Middle and Callahan Elementary – were immediately put into lockdown.No injuries were reported.Tran was not in possession of a firearm when he was arrested at the school Thursday, police said.