An inquiry into the killing of Bailey Gwynne is under way six months after he was stabbed to death at school.

The 16-year-old was stabbed through the heart by a fellow pupil at Cults Academy in Aberdeen on October 28.

Glasgow child protection chief Andrew Lowe will head up the review, which began on Tuesday and is expected to last five months.

It will attempt to establish the relationship between Bailey and his killer and will examine the actions of social care agencies.

His killer, who cannot be named for legal reasons, was charged with murder but found guilty of the lesser charge of culpable homicide at the High Court in Aberdeen.

The teenager was also found guilty of carrying a knife and knuckledusters in school and was sentenced to nine years detention on April 1.

On the first day of the trial, Cults Academy head teacher Anna Muirhead said she warned Bailey's killer about the dangers of bringing weapons into school several years ago.

Despite her advice, the 16-year-old said he regularly carried a knife in an attempt to "act tough" and "be cool". One witness said they had seen him with a knife up to 25 times before the killing.

Aberdeen City Council said it had never been reported to teachers and claimed staff were not aware of the problem.

The inquiry is expected to report its findings in September.