Kerry (L) and Emma (R) Maguire react after the funeral service of their mother, school teacher Ann Maguire at the Church of The Immaculate Heart of Mary in Leeds, northern England May 16, 2014.
Kerry (L) and Emma (R) Maguire react after the funeral service of their mother, school teacher Ann Maguire at the Church of The Immaculate Heart of Mary in Leeds, northern England May 16, 2014. A 15 year old boy has been charged with the fatal stabbing of Maguire at Corpus Christi Catholic College in Leeds, about 175 miles (280 km) north of London on April 28. REUTERS/Phil Noble

Will Cornick was 15 when he stabbed 61-year-old Leeds teacher Ann Maguire. He has been sentenced to prison imprisonment for life. He hit her seven times in the back and neck at Corpus Christi Catholic College. He then sat down and exclaimed that it was the beginning of "good times," according to BBC.

He is expected to be one of 1,183 people under 18 in detention, according to recent statistics. Moreover, it is expected that he would also be among the most "notorious," due to the nature of his deeds, according to The Guardian.

Apparently, he hated the teacher, he had told all his classmates, said the Leeds Crown Court. The judge commented on his "chilling lack of remorse" and sentenced him to 20 years, adding that he may not even be released after that. Last year, being 15 had exempted him from being identified, but Justice Coulson openly named him this year. He stood in the dock with prison officers on either side while the clerk read out the charges against him. He just stared without emotion as he admitted to murdering his teacher.

She had got seven stabs on her back and neck. While she was bending over her desk to help another girl with her work, Will winked at someone else in the room and then attacked her from behind. His prosecutor, Paul Greaney QC, commented that he seemed to show some psychopathic tendencies, and he also appeared to be happy about the public nature of the murder. Even the students had noticed a disturbed personality in him. However, his mental condition was not enough to justify or mitigate the "horror" of his act, according to Independent.

He had hated Maguire and wanted her dead. He wrote on Facebook that she "deserves more than death, more than pain and more than anything that we can understand." The prosecutor said that Will had written in a message that by killing Ann, he would not have to "worry about life or money."

He had held a large kitchen knife, and committed the cowardly act that brought no justice. Ann tried to run, but he just stabbed her as she tried to escape.Her colleague Susan Francis heard the children screaming and rushed to help her friend, took her into a work room and shut the door. Cornick just walked back to his classroom and sat down "as if nothing had happened", the prosecutor said. Later, he bragged that he was proud of having murdered the teacher. He said he did not bother about the effect on her family, either. "In my eyes, everything I've done is fine and dandy," he said.

However, no one could understand why he had done it. His parents are "decent and responsible," according to the prosecutor. Not understanding why this has happened, they have cooperated with the prosecution.

Don Maguire, Ann's husband, called it "evil." Ann had taught in the school for 40 years and was about to retire. In the court, Don called it a "monumental act of cowardice and evil."