But a new book is attempting to lay to rest one of the most controversial aspects of the trial and execution of multiple murderer Peter Manuel: did he deserve to hang?

Manuel was sent to the gallows in 1958 after being convicted of seven murders in Lanarkshire and Glasgow that put the west central belt of Scotland into a state of alarm for more than a year. His modus operandi was to break into homes and slaughter the sleeping occupants in their beds by shooting them at close range in the head. Criminologists studying the case used the term "serial killer" for the first time to describe his murder spree.

But controversy has raged since his trial over whether the petty criminal-turned-murderer was suffering from a mental illness or other medical condition at the time of the killings. Such a diagnosis could have allowed Manuel to plead diminished responsibility and escape the hangman's noose.

Earlier this year, on the 50th-anniversary of Manuel's execution, an Aberdeen-based academic, Dr Richard Goldberg, said he was told that Manuel had been diagnosed as having a form of epilepsy that could have led to "black-outs" during which he was unaware of his actions. This "evidence" was never heard in court.

But the authors of the new book say an exhaustive examination of medical reports compiled by six psychiatrists and other doctors at the time, including a neurologist, show that while all agreed Manuel was a psychopath – in other words suffering a personality disorder – he did not have any mental condition that could have been responsible for his actions.

The book, to be published by Mainstream next year, is the most comprehensive examination of medical documents, prison records and witness statements related to the case to be undertaken. The authors are Professor Malcolm McLeod CBE, a social anthropologist and former vice-principal of Glasgow University, and Hector McLeod (no relation), an experienced Scottish lawyer.

Prof McLeod said: "There was agreement that Manuel was a psychopath who was culpable for his actions. He was under no delusions when he killed and did it because he wanted to do it. The reward was power and the feeling of invulnerability and cleverness when, in the early days, police could not pin the murders on him.

"It was claimed recently that he may have been suffering from temporal lobe epilepsy, but I don't believe that. There is no evidence in the medical reports to suggest that. Six psychiatrists said he was fit to stand trial.

"In fact, all the evidence suggests he was not suffering from any form of epilepsy. If he was somehow unaware of what he had done, why did he go to such lengths to cover up his crimes and try to mislead the police by scattering the possessions of his victims around?"

But this verdict appears to contradict the claims of Goldberg, a lecturer at Aberdeen University's School of Law, the son of Professor Sir Abraham Goldberg, the former Regius Professor of Medicine at Glasgow University, who died last year. He says that his father told him the results of an electroencephalogram (EEG) examination that Manuel underwent at the Western General Infirmary on February 16, 1958, five months before his hanging, conducted by a personal friend, Dr John Gaylor.

Goldberg said the EEG showed abnormal wave patterns in Manuel's temporal lobe that could indicate epilepsy. "This is questionable," Goldberg said. But until we get clarification of this then it remains a possibility. I was told this by my father and I have no reason to doubt him.

"If Manuel did have a defective temporal lobe then it could have been relevant as to whether he hanged or not. But Gaylor's evidence was never heard in court because Manuel dismissed his QC and conducted the case himself." He added: "I do not want to be seen as an apologist for Manuel. But his is such an important case that we really do want to establish what was going on in his brain."

Manuel's first victim was factory machinist Anne Kneilands, 17, in January, 1956, who he beat to death as she walked home in East Kilbride. He then killed three members of the Watt family in Glasgow and another teenager, Isabelle Cook, in 1957.

He was caught only after the subsequent murder of three members of the Smart family in Uddingston in January, 1958.

After a trial at the High Court in Glasgow the following May, Manuel was convicted of seven murders, but cleared through lack of evidence of killing Anne Kneilands. After his execution, he was convicted of killing Newcastle taxi driver Sydney Dunn.