A 16-year-old Trumbull High student is under arrest after police said she made an online threat to \u201cshoot up\u201d the school. The student was arrested March 14, the same day students participated in a school walkout to protest school violence. Police were notified of the incident when concerned students and staff members approached a school resource officer with evidence of the threat on a social media site. The student had made other comments online, in addition to the shooting threat, police said. Upon further investigation, a photo of the student was also linked to the threat, which showed the student holding what appeared to be a handgun. Police then located a replica gun in the student\u2019s home and determined it was the one from the posting but it was not a functioning firearm. The student was charged with threatening and breach of peace and was referred to juvenile court. The student was released to parents and there is an ongoing investigation to determine if others were involved.