In alanabit's post of 16 Mar 04 - 03:35 PM, he says:

"A murderer who leaves so much evidence around that his conviction cannot be in any doubt is in fact a bloody fool. However, a truly devious, calculating murderer sets out to leave very little evidence indeed."

It can go a bit further than that, as in the case of Timothy Evans (who was not the brightest of people). The real murderer was Christie, who ensured that there was enough evidence left around to implicate Evans. Under any justice system based on jury trial whoever is sat in the dock is judged by the weight of evidence brought against them. Mistakes and miscarriages of justice are inevitable, I prefer a system where such mistakes can be rectified.