A second teenager has been arrested in connection with the fatal stabbing of Spanish teacher Ann Maguire in her classroom in Leeds.
West Yorkshire Police confirmed the boy was arrested and later released without charge.
The force would not confirm what offence he was arrested on suspicion of, but said it was not murder.
Meanwhile, the 15-year-old boy who is accused of carrying out the stabbing is due to appear before a judge today.
The teenager will appear by video-link at Leeds Crown Court, a day after he appeared at the city's Youth Court, accused of murdering Mrs Maguire, 61, at Corpus Christi Catholic College on Monday morning.
Yesterday, her husband, Donald, stared intently at the youth during the two-minute hearing.
Mr Maguire, 62, sat between his daughters, Kerry and Emma, at the back of the courtroom and clutched their hands as the boy stood in the glass-fronted dock flanked by security guards.
The family released an emotional tribute to the long-serving teacher, describing her as "our shining light".