They Do It With Mirrors +CD (Agatha Christie Readers)

There is a dangerous atmosphere at Stoneygates, a centre for young criminals. When Miss Marple visits her friend there, she can sense the danger, too. One evening during her stay someone shoots at the administrator of the centre. He is not injured, but a visiting relative is shot dead at the same time in another part of the building.

Could this be a coincidence? Miss Marple must solve the mystery.