En route to his friend’s house in Glasgow at midday on June 1 last year he bought a pint of milk from Iceland – an act so routine that it would raise no-one’s suspicion.

He then took a taxi under a false name to visit Kusbu Shah, 23, his friend’s wife in Dennistoun. Mrs Shah had only met Dantis once previously but knew that he and her husband were close friends.

Then he took a taxi home, met his wife Astrid and went to see the latest blockbuster at Cineworld on Renfrew Street.

Later that evening he went online and renewed his loan of Kathy Reichs’s book, Devil Bones, that he had borrowed from Strathclyde University.

It seemed like the most ordinary of days for the Strathclyde University masters student.

However, it was while at his friend’s house that he committed a murder he had spent more than six weeks planning.

After the young, 5ft 1ins mother opened the door, Dantis restrained her, put tape over her mouth, attacked her with a cleaver, strangled her and severed her head and hands. In the bath he drained her body of blood, following procedures he had read about in both Reichs’s book and the Forensic Case Book, which he also had at home.

Shortly afterwards he sent an anonymous text message to his classmate and friend Nagendra Shah using the mobile phone of the woman he had just killed. The text said his wife had been abducted.

Dantis, 30, had only been in the country for nine months. Originally from Goa in India, he and his wife Astrid were in Glasgow while he studied for a masters at Strathclyde University.

At night he worked as a security guard for G4S and was based predominantly at Celtic Park. By day, the engineering student, was studying business. His entries to online forums suggest he was interested in attending further courses in information technology. It was while on the masters course that he met Nagendra Shah and his wife.

The Shahs had recently sold a property in London and were thinking about opening a restaurant in the Shetland Islands. They owned a car and television and had a four-year-old son called Nikhil, while Dantis lived in “straitened financial circumstances”.

Jealousy is thought, in part, to have driven his actions.

In April last year Dantis began to make lists. One such list detailed what he needed to buy and included a Chinese meat cleaver, a balaclava, bleach, DIY tape and a clothes cover.

He also compiled a set of instructions labelled “chain of events” including “change to other clothes”, “wait in room” and “finish the job”. In Argos he bought the holdall that he would ultimately use to dispose of Mrs Shah’s torso.

Computer experts found that he had also visited Strathclyde Police’s website and accessed a web page named “suspicious death Dennistoun” and, on June 7, he had searched for free legal aid in Glasgow.

Reichs’s book, which focuses on a forensic pathologist’s investigation of ritualistic killings in the US, proved to be a major part of his inspiration and set the tone of his own modus operandi.

In it the pathologist, Dr Temperance Brennan, discovers sacrificial Voodoo and Santeria paraphernalia, cauldrons and a decapitated torso drained of blood. The investigation ultimately reveals that the cauldrons are a red herring being used to confuse the police.

When Nagendra Shah, 32, received a text message saying his wife had been abducted he was terrified. His wife had failed to meet him at lunchtime as planned and the text was from her phone. It said: “We have your wife. Don’t call police we are watching you. If anyone is told we will kill her and you.”

It went on to instruct him to arrange for £120,000 to be gathered and for him to go immediately by train to London.

The message also stated: “No compromise or you all die. Further instructions will follow soon once you are in London. Delete this message, no records to be kept. Nobody will be harmed if you follow instructions.”

As a means of proving he would be willing to co-operate he was told to take his television and sell it to one of his university classmates – a Mr Dantis – and that the abductors would be watching.

Distraught, when Mr Shah spoke to his close friend Dantis he urged him to pay the money and not contact the police. Ignoring his advice he telephoned the police and remembered Dantis’s face went dark.

Strathclyde Police began a major kidnap inquiry involving more than 100 officers and round the clock surveillance teams.

Dantis was placed under surveillance as the suspected kidnapper but officers believed he was working with others. They watched him go into the Trongate and buy another Sim card. Still believing Mrs Shah was alive, police couldn’t understand why he did not seem to be contacting anyone else.

Then another text was sent. It said Mr Shah had not done what he was told to do and that he would never see his wife again.

A forensic search of the Shahs’ home unearthed spots of the victim’s blood. About 30 yards from the back door, officers found a holdall containing the body of Mrs Shah, minus her head and hands. Within a day DNA found on the handles has been matched to Dantis.

“The whole focus was to try to establish where she was being kept,” said detective superintendent Michael Orr of Strathclyde Police. “It was a massive operation with well in excess of 150 officers and support from a number of agencies.

“Ultimately it was very disappointing to find that she had already been murdered.

“I don’t know of any case in Scotland with evidence to suggest this level of pre-meditation. We know that he was planning this in great detail five to six weeks in advance because of the detailed lists he made. Jealousy, financial gain and fantasy may all have been motives.”

When questioned Dantis denied involvement and showed no remorse. Officers found the meat cleaver, gloves and remains of Mrs Shah on a railway embankment near Celtic Park.