They believe Valdo Calocane, although mentally ill, knew what he was doing and should have been convicted of murder and sent to prison.

They were also angry about his sentencing and called for it to be referred to the Court of Appeal.

It found his sentence was correct and had not been unduly lenient.

Afterwards, Barnaby Webber’s mother, Emma, said in a statement: “We do not and never will agree that the vicious, calculated and planned attacks carried out were that of an individual who was at zero level of capability.

“We have never disputed that he is mentally unwell; however, he knew what he was doing, he knew that it was wrong; but he did it anyway. There should be an element of punishment for such a heinous act; alongside appropriate treatment.”

Brian Dow, deputy chief executive of the mental health charity Rethink Mental Illness, believes the state of mental healthcare in the UK has made tragic outcomes inevitable.

“Looking back, it was a question of when, not if. And unless we both invest and change the model of healthcare that we have, so we don’t allow these crises to build up and build up, then there’s the inevitable risk that this will happen again,” he said.