A Huffman High School student is in custody in the fatal shooting of 17-year-old Courtlin Arrington inside the east Birmingham school. 
 
 Police have not identified the student but issued this statement Thursday morning: "Detectives of the Birmingham Police Department have been working through the night reviewing evidence, video and statements on the tragic incident that took place at Huffman High School yesterday. Due to their diligent work a person of interest has been taken into custody. Charges are pending a review of the case by the Jefferson County District Attorney's Office. Because the charges are pending we will not be releasing any information on the individual in custody. Further information will be released as it becomes available." 
 
 Was the shooting an accident? 
 
 Initially Birmingham police officials said the deadly shooting, which happened inside a classroom as school was dismissing for the day, appeared to be accidental. 
 
 "At this particular time, we consider it accidental until the investigation takes us elsewhere,'' Acting Birmingham Police Chief Orlando Wilson said. "We have a lot of unanswered questions. There are so many unknowns at this time." 
 
 We learned Thursday that the shooting was captured on video and led authorities to pursue the charges against the student. 
 
 Were metal detectors being used at the school? 
 
 Dr. Lisa Herring, Superintendent of Birmingham City Schools, said Huffman High School does have working metal detectors in use but declined to comment further as it is part of the ongoing investigation. 
 
 We don’t know if the metal detectors are the kind that students walk through or if they are the wand type often used in secondary inspections. 
 
 Are there cameras in the school? 
 
 Acting Birmingham Police Chief Orlando Wilson said Wednesday that there were surveillance cameras in the school. 
 
 Who was the third person that was injured? 
 
 A third person, who is not a student, was injured, but it is unknown to what extent. 
 
 What does “person of interest” mean? 
 
 A person of interest is someone the police are “interested” in during the proceedings of a criminal investigation 
 
 Terms like “suspect,” “target,” and “material witness” are more clearly defined, and even have formal definitions given to them by the Department of Justice. However, “person of interest” remains undefined formally. It does not show up in formal manuals like the Associated Press Stylebook, which reporters use to aid them in writing their stories, and it has never been officially defined by police, prosecutors, or journalists. The term is more of a colloquialism, rather than an official definition. 
 
 Were parents notified of a lockdown? 
 
 We have asked Adrienne Mitchell, Birmingham City Schools Strategy and Communications Officer, but have not received a clear answer. When asked if parents were notified, she referenced a recorded message sent to parents hours after the shooting. We have asked if an alert was sent to parents alerting them to a lockdown and subsequent shooting. We have not received a response to that question. 
 
 Students interviewed by WBRC said the bell rang at 3:40 p.m. and the gunshots occurred around 3:45 p.m. The school was placed on lockdown at that time. 
 
 Copyright 2018 WBRC. All rights reserved. ||||| A Huffman High School student is in custody in the fatal shooting of 17-year-old Courtlin Arrington inside the east Birmingham school. 
 
 Police have not identified the student but issued this statement Thursday morning: "Detectives of the Birmingham Police Department have been working through the night reviewing evidence, video and statements on the tragic incident that took place at Huffman High School yesterday. Due to their diligent work a person of interest has been taken into custody. Charges are pending a review of the case by the Jefferson County District Attorney's Office. Because the charges are pending we will not be releasing any information on the individual in custody. Further information will be released as it becomes available." 
 
 Initially Birmingham police officials said the deadly shooting, which happened inside a classroom as school was dismissing for the day, appeared to be accidental. The shooting, however, was captured on video and led authorities to pursue the charges against the student. 
 
 There was a bit of confusion on police radios at first with reports of an active shooter. An officer then clarified the situation. "Listen. We've had an accidental shooting, not an active shooter. We have the gun, we have the one who had the gun. We just need two paramedic vehicles to get these two kids out." 
 
 The shooting happened at 3:45 p.m. Arrington was given CPR at the scene and en route to UAB Hospital but was pronounced dead upon arrival at 4:16 p.m.. The other teen suffered a self-inflicted gunshot wound to the leg. He was treated in the emergency room and quickly released into police custody where he was questioned and held overnight in the Birmingham City Jail. 
 
 A woman at the police station who said she was the boy's mother, said she had not been told his condition, but she did not believe he had a gun. She and other family members gathered there declined further comment. Friends of the student said he had been robbed on campus the previous day, and that likely is why he had a gun at school. 
 
 Arrington was going to graduate in May, had already been accepted into college and had dreams to become a nurse. "We're not just talking about some person, we're talking about losing a part of our future,'' said Birmingham Mayor Randall Woodfin. "Our hearts are heavy." 
 
 On Thursday, the mayor asked that all flags at city facilities be flown at half-staff. "My thoughts and prayers remain with this young lady's family, friends, Huffman family, and community,'' he said via Twitter. 
 
 School officials announced late Wednesday night that school will be closed on Thursday. The delay will provide an opportunity for the system to conduct a thorough safety sweep of the school, and also allow the system to collaborate with organizations in the community to provide counseling support to both students and staff, said Superintendent Lisa Herring. 
 
 "The magnitude of this event causes us to pause," Herring said. "However, we want to assure our parents, students, staff and community that safety and security are a top priority for Birmingham City Schools." 
 
 On Thursday, Herring met with Acting Police Chief Orlando Wilson and his staff to come up with a safety plan for heightened security when students return to school on Friday. In addition to the school resource officers already assigned to the school, additional officers will patrol both the inside and outside of the school. A number of other undisclosed safety measures also will be put into place, she said. 
 
 The superintendent also said school district administrators are meeting with United Way, area pastors, local teacher association representatives, mental health counselors and others to devise a counseling plan for students and staff. 
 
 "We recognize that as the students return on Friday, that will not be an instructional day,'' Herring said. "We recognize that this is a time of crisis and students are processing emotions that many have never dealt with. It is important to understand that Friday, and the coming days, will be a day of comfort and support." 
 
 Many have questioned the use of metal detectors at the school, and whether they were in use Wednesday. Herring said she wouldn't comment on any part of the ongoing investigation, but said there are working metal detectors at the school. 
 
 Herring said she knows there are many tough days and tough questions ahead. 
 
 "Our goal is to reassure our parents that, as much as we can, we will work to keep our schools safe. But our hearts and our minds are on the families tonight,'' she said. "How do we tell parents that their school is safe after an event like this and how do we reassure our children? That is the work we will take on every single day." 
 
 Herring said Huffman High School does have working metal detectors in use but declined to comment further as it is part of the ongoing investigation. In addition to increased security at the school Thursday, the superintendent said said there will be a full crisis team on hand to help students and faculty. 
 
 She praised the school officials on hand during Wednesday's shooting. "For as much as they've had to tackle on a very difficult day, they have done an exceptional job of trying to provide care and concern for those who were in the building and for those who had exited out,'' she said. 
 
 "We had two victims today, regardless of the circumstances,'' Herring said of both students. "We are most concerned about our families and the child who is no longer with us. We will not only pledge every effort to support the family, but we will do that for every child in Birmingham City Schools." 
 
 "I think it's really important we find a way to mourn with the family. That we wrap our arms around the Huffman High School community,'' Woodfin said. "Our entire Birmingham community is in mourning and grief right now. While there are many questions ...we need to take to the time realize that a life was lost. " 
 
 Dozens of police officers gathered at the school Thursday morning, as the investigation into yesterday's fatal shooting continues. A small memorial of red balloons and flowers were placed on the fence, near the school's driveway. 
 
 Birmingham City Councilor Lashunda Scales, who represents the Huffman area, was also present Thursday. She commented on what she thinks the school can do to increase security, and said Arrington had a "beautiful, radiant smile." 
 
 Denise Kendricks, who lives in Huffman, stopped by the school Thursday morning to voice her concerns about security measures in place. "These kids are out here crying for our help," she said through tears. "Something has to happen. Somebody's got to be held accountable." 
 
 Kendricks has a son, who serves in the military and lives in Florida, a daughter who recently graduated from Auburn University, and a six-year-old who goes to school nearby. None of her children went to Huffman High. "I expect my child to come home [from school]. I never expect my child to not make it home," she said. "I can't even wrap my brain around that." 
 
 The woman also said she's frustrated with others offering prayers and setting up vigils. She said, "We're past candlelight vigils. It's too late for that. Where were you yesterday? Where were you the day before yesterday?" 
 
 "These are the things [students] are seeing every single day.... I'm tired of people waking up and losing their lives over something that could be handled," Kendricks said. "If it's affecting our community, it's affecting me." ||||| A person of interest has been taken into custody after a 17-year-old girl was shot dead at an Alabama high school Wednesday, police said. 
 
 Charges are pending a review of the case by the Jefferson County District Attorney’s office, the Birmingham Police Department said today. 
 
 A 17-year-old boy was also shot and survived in the Wednesday afternoon incident during dismissal at Huffman High School in Birmingham, police said. He was taken to a hospital where he was treated and released, police said. 
 
 Carol Robinson/AL.com via AP 
 
 Carol Robinson/AL.com via AP 
 
 The cause of the shooting remains under investigation, Peter Williston of the Birmingham Police told ABC News today. 
 
 The gun involved was recovered, police said. 
 
 Carol Robinson/AL.com via AP 
 
 Brynn Anderson/AP 
 
 Police today did not release any information about the person in custody. 
 
 Alabama Gov. Kay Ivey said on Twitter Wednesday, "I'm praying for the family of this young lady who tragically lost her life way too early." 
 
 ABC News' Rachel Katz and David Caplan contributed to this report.
– A 17-year-old student is in custody as a person of interest in Wednesday's fatal shooting at an Alabama high school, AL.com reports. According to ABC News, police are pursuing charges against the teen but aren't releasing any additional information on his or her identity until charges are filed. The person of interest was also one of the two students injured in the incident, which happened during dismissal in a classroom at Huffman High School in Birmingham. The teen reportedly shot themselves in the leg. They were released from the hospital and into police custody. The 17-year-old killed in the shooting has been identified Courtlin Arrington. She was set to graduate in May, had been accepted to college, and hoped to become a nurse. A third, non-student person was injured in the shooting and treated at the scene, WBRC reports. Police initially called the shooting "accidental," though the cause is still under investigation. Officials decided to pursue charges after watching video of the incident. "At this particular time, we consider it accidental until the investigation takes us elsewhere,'' acting Birmingham police chief Orlando Wilson says. "We have a lot of unanswered questions. There are so many unknowns at this time."