Massacre in May?

A man was convicted of murder and sentenced to spend 18 years in prison even though the body had never been found. The man's aged mother visited him in prison. She was distressed, not only because her son was suffering the privations of incarceration, but because he had always dug her garden in the spring ready for her to plant vegetables.

Five days after her visit, half a dozen burly men turned up on her doorstep and proceeded to dig up the whole of her back garden. Her son had made sure a warder overheard his whispered conversation with another prisoner concerning the missing body's location. What a good son he had turned out to be.