Etta is the heroine in The Case of the Locked Drawer

She is 92 years old. She solves crimes unsolved by police authorities. Her present challenge is a victim slumped over a desk in which a locked desk contains the murder weapon. In two years the police have not solved the crime. Etta is wheelchair bound. She uses her telephone, her computer and her wits to solve crimes. Can you solve this crime before she does?