Researchers at Leicester University have discovered startling proof of what could be a dramatic new key factor that nearly all murderers share.

The study, for which over 2,500 imprisoned killers have been interviewed, has the potential to revolutionize the science of criminology, as well as possibly dramatically reduce the murder rate worldwide.

Previously, it had been widely understood that social factors play a large part in shaping a killer, with influences such as violent movies, physical or sexual abuse, and the trauma of witnessing war during childhood cited. This new study went a step further, and sought to identify something that all killers had in common.

And, according to lead researcher Doctor Dick Trafford, it has succeeded. Every single killer surveyed shared a single, common factor. Each one had eaten potatoes, or potato based products, at some point in their lives before they committed murder.

“You don’t get a 100% common factor by accident” an excited Dr Trafford told reporters, “If all killers share this single trait, it is more than just coincidence……And, over such a large base of research, this is categoric proof that the potato is an overwhelming factor in murder cases”.

Victims rights groups have been fast to call for all potato products to require that a purchaser is over 18, and for it to be made a criminal offence to supply a potato to a minor. Some groups have gone further, arguing for an outright ban, saying that it is the only way to reduce violent crime in our society.