The killer was a "taxi boy", a teen sex worker whose short life was summed up in court as  "a string of trauma, abuse and abandonment."

His victim was a distinguished 60-year-old Scottish violinist and conductor who had picked him up.

In August 2017 Alan Torres, then just 19, tied up and gagged Glasgow-born Finlay Ferguson in Cordoba, Argentina.  He then - with what a court decided was 'malice aforethought" - smashed the father-of-two's head with a dumbbell. He was caught a day later with Mr Ferguson's phone. 

This week the youth, still only 21, was jailed "in perpetuity", Argentina's toughest sentence, for aggravated homicide. He will spend, local media said, at least 50 years in prison.

The "Finlay Ferguson case", with its horrific and tragic details and well-respected victim, has shocked Argentina.

Representing Mr Ferguson's family, lawyer Martin Freseda - his tie undone and with an air of sad fatigue, told TV news that the perpetual prison sentence was merited because the crime was so "terrifying" and "gruesome".

He said: "Finlay Ferguson was unarmed with no possibility of defending himself." 

HeraldScotland:

Alan Torres in court, screen grab from Argentina's Telefe Noticias news channel

Prosecutors were uncertain whether Mr Ferguson - who had recently split from his wife - had met Torres before. There was some indication that the pair had been in contact. The murder  took place in Mr Ferguson's flat and was initially reported as a "crime of passion".

READ MORE: Scottish conductor murder probe as teenager arrested after death in Argentina

Torres's defence had argued the youth, filmed in court, did not understand what he was doing, Mr Freseda said, that he had not been culpable for his actions.

Prosecutors, however, successfully argued the crime was pre-meditated murder for theft. They cited his Torres; cold-blooded actions after the killing. He took a ring from Mr Ferguson's dead finger and loaded the chip from his own phone in to the one he stole from the musician.

Mr Ferguson's laptop was later found in Torres' home. 

READ MORE: Scottish conductor Finlay Ferguson found dead in apartment with head wounds

Mr Ferguson had lived in Argentina for 30 years and was a well known fixture in the country's classical music scene. He was director of the San Martin Theatre Youth Academic Orchestra in Cordoba and a former gold medal winning student at the Royal Scottish Academy of Music and Drama.

Speaking after his death, Mr Ferguson's daughter Celina said: "Music was his all-consuming passion.

“He was always very grateful to how the school system in Scotland was at the time, because when he was in secondary school he was able to devote practically all his time to studying music and at the end only attended history lessons just because he liked it.

“He was a really curious and extremely intelligent person who liked to learn and read about everything.

“He transmitted his passion for teaching to lots of his students who are now themselves violin professors, carrying on the legacy of their maestro.”