His mind was spinning. Was there a connection with his brother being in prison? All his experience and instinct told him there must be. He turned to the Crime Scene Manager. ‘Any idea how they got in, Alex?’

‘No, sir. None of the door locks were forced and there are no broken windows. The victim must have opened the front door and let his killers in.’

Grace nodded. ‘That fits with what I know about Down’s Syndrome from a previous case – some years ago. They are lovely, trusting people. He’d have probably opened the door and welcomed them in.’

‘So why would anyone have wanted to kill him?’ Call asked.

‘His brother’s on remand, charged with one of the biggest drug importations in Sussex history. Maybe his associates or rivals came here looking for cash or drugs and got surprised by Stuie?’

Grace paused, thinking, looking down at the body that was like a broken, bleeding rag doll. ‘If they were surprised by him, Alex, they might have knocked him out or tied him up. Why would they have done this?’

‘I agree with you, sir. This isn’t how you’d deal with someone who surprised you.’

Grace shook his head. ‘No, it isn’t. This was savage, way over the top.’

‘Do you think they might have killed him to stop him from identifying them?’ Call ventured.

‘Possibly, Alex. That’s one hypothesis. But maybe there was something else going on.’

Grace turned and looked out of the window, which overlooked a small, fenced-in garden, with a recently mown lawn and a shed at the far end. There was a basketball net on a post, with a white ball lying in the grass.

He walked across the room, over the landing and into the room opposite, which was a similar size. The bed sloppily made, the counterpane pulled over unevenly. On the bedside table sat the memoirs of Muhammad Ali. On a shelf was a row of books on boxing, and a photograph of a man in his late twenties in a boxing ring, gloves raised, head down. Hanging from a hook on the wall opposite was a pair of boxing gloves.

Grace went back out and into a third, much smaller room which appeared to be a den. There was a laptop dock on a table, with an ergonomic chair pulled up to it. Below was a set of drawers. Nothing in here looked like it had been touched. Next, he went into the bathroom. Two towels lay on the floor, another was draped over the side of the bath. The showerhead lay in the bath, at the end of its metal hose.

What had been cleaned up in here? Or who?