AS a seven-year-old boy, Donald Findlay was influenced by two starkly different men: one was Michael Denison, star of television legal drama Boyd QC; the other was Lanarkshire serial killer Peter Manuel.

When Manuel stood trial at the High Court in Glasgow in 1958, a young Donald devoured every word from his home in Glenrothes, Fife.

Much to the embarrassment of his father, he was able to recite the charges and names of victims as other youngsters would rattle off nursery rhymes.

"I'm not saying I understood it in any great depth but I was drawn to it and knew it was something unique," says Donald.

Each day he would scour the newspaper for stories about the case. "In those days, big trials were reported almost verbatim. Even when I started off big trials were covered in detail. Whereas now they get three lines next to the Milton Keynes dogs."

Around the same time a relatively new TV show called Boyd QC captured his imagination.

"Michael Denison played this barrister who was for the underdog and against the establishment. That was the first thing that attracted me to the law."

Donald, 65, has served as a defence lawyer in many high-profile cases including the Jodi Jones, Mark Scott and Kriss Donald murder trials.

He also represented Peter Tobin, who was convicted of murdering Polish student Angelika Kluk at a church in Glasgow in 2006.

Manuel's reign of terror lasted two years and claimed at least seven victims across Glasgow and Lanarkshire between 1956 and 1958.

Marion Watt, 45, her 16-year-old daughter Vivienne and her sister Margaret Brown, 41, were shot dead in their home in Burnside, Rutherglen, on September 17, 1956.

On December 28, 1957, Isabelle Cooke, 17, disappeared after leaving her home in Mount Vernon, Glasgow, to attend a dance at Uddingston Grammar School. Manuel strangled her and buried her body in a field.

His next victims were Peter Smart, 45, his wife Doris, 42, and their 10-year-old son Michael, who were shot dead in their Uddingston home on January 1, 1958. After the murders, Manuel stayed in the house for almost a week, eating leftovers from their Hogmanay meal and even feeding the cat.

It is also believed that Manuel murdered 17-year-old Anne Kneilands two years earlier who was found bludgeoned to death with an iron bar on an East Kilbride golf course on January 2, 1956.

Following a 16-day trial at the High Court in Glasgow, during which Manuel dramatically sacked his lawyers and conducted his own defence, he was convicted of seven murders on May 29, 1958.

The judge had ruled that Manuel's confession to the murder of Anne Kneilands was inadmissible. After a failed appeal, Manuel was hanged on the Barlinnie gallows at 8.01am on July 11.

Donald says Manuel remains one of the few true serial killers to have come through the Scottish legal system.

"Peter Manuel, certainly in my lifetime, is the only genuine serial killer that we have ever had," he says. "People have killed more than once, perhaps even more than twice, but that doesn't necessarily make them serial killers."

The term psychopath, says Donald, is another that is often bandied about. "Manuel was a psychopath and arguably the only genuine psychopath that has featured in the criminal justice system.

"Others have perhaps been borderline but Manuel was a genuine psychopath. Put all that together and you have something quite unique."

Donald doesn't believe Tobin, who is serving three life sentences for murdering Kluk, Falkirk schoolgirl Vicky Hamilton and Essex teenager Dinah McNicol, can be labelled a serial killer.

"There is no evidence of Tobin being a serial killer. He is someone who, according to convictions, has killed more than once, but that doesn't make you a serial killer."

Nor is he convinced that Grangemouth-born Robert Black, who was convicted of the kidnap, rape, sexual assault and murder of four girls during the 1980s, falls into that category.

"Black perhaps approaches it, but I'm not convinced he is a serial killer. The problem with Black is that he had a thing for kids – serial killers don't have a thing for anybody. They just kill almost for the sake of it.

"Jack the Ripper was a man who killed a lot of prostitutes. Does that make him a serial killer? Not in my book. It makes him a prostitute killer. Black killed kids. That makes him a child killer.

"Whereas Manuel killed old women, young women, men, families. The only explanation you could give was because he could. He didn't get any financial gain.

"There is no real evidence that he got a sexual kick because raping people didn't feature in Manuel's makeup," he adds.

"He was someone who killed because he could. It gave him power and control."

If Donald could have met Manuel, what would he have asked him? "Waste of time," he says. "He would tell you one thing and change it later because the true psychopath would see it as a power struggle.

"If he tells you the truth, then he loses his power. He would take you up and down endless blind alleys. It would be fascinating to watch him playing you, that game of cat and mouse.

"The skill would be trying to turn yourself into the cat and him into the mouse."

With the new ITV drama, In Plain Sight, due to begin on Wednesday evening, it does not seem that the macabre fascination with Manuel will fade soon.

"Life is very strange, is it not, that an evil ned from Lanarkshire kills people, is hanged and should have disappeared and yet here we are, 60 years on, making a television programme about him?

"If you are looking for a bizarre immortality, then that is the way to achieve it."