Claudio Valente was long hailed as Portugal’s most promising physicist of his generation.

However, his former classmate, Nuno Loureiro, went on to establish a distinguished career in the United States, a path that Valente could not follow. Tragically, Loureiro’s success ended in a fatal encounter driven by professional envy.

“This was not a rivalry that developed between two individuals,” stated Bruno Soares Gonçalves, president of the Institute of Plasma and Nuclear Fusion at the University of Lisbon. Both Valente and Loureiro once studied there. “It was a conflict that grew within one person.”

The shocking event unfolded on December 16, when MIT professor Loureiro, aged 47, was fatally shot in Brookline, Massachusetts. Authorities identified the shooter as Valente, 48, a former academic prodigy once celebrated as one of Portugal’s most brilliant scientific minds.

Valente was later discovered deceased in a storage unit in Salem, New Hampshire, in what police reported as a suicide.

Valente was eventually found dead in a storage locker in Salem, New Hampshire,  after taking his own life, police said. 

He has also been identified as the gunman who opened fire in a Brown University physics classroom, killing two students, on December 13.

Although Loureiro and Valente studied together in Lisbon in the late 1990s, former classmates and senior academics say there is nothing to suggest they maintained any personal or professional relationship in the ensuing decades.

Instead, former colleagues from Portugal painted a picture of an immensely talented physics student with great promise – Valente – who spiraled downward after coming to the US to study at Brown University in Providence, Rhode Island.

Valente’s squandered career was in marked contrast to Loureiro’s professional trajectory that culminated in him being named director of the MIT Plasma Science and Fusion Center last year.

Loureiro lived a life of apparent professional achievement and domestic tranquility with his Portuguese-born wife, Ines Costa, and their three daughters, in a condo in Brookline. 

Ines’s mother was visiting at the time her son-in-law was brutally ambushed at the family home and gunned down.

Family friend Eurydice Hirsey told the Daily Mail she knew Ines because the two were in a local dance troupe together, and described her as ‘lovely and fun with what seemed to be a very happy family.’

Hirsey and Ines walked home together from their dance class on December 18.

‘At one point we both turned in different directions to go to our homes and we said, “see you Wednesday”,’ she said.

‘I figure it was only about 20 minutes after I said goodbye to her that Nuno was murdered. We’re all going to the house to visit her when we can. 

‘She just seems to be in shock. I can’t even process it myself, it’s so devastating.

It’s not clear if Valente ever married or had children.

What has emerged from interviews across Portugal and from former colleagues abroad is a portrait of two lives that began in the same classrooms but moved in radically different directions.

Loureiro moved steadily upward in the field of physics while Valente withdrew and appeared to have unresolved resentment, according to several who knew him.

Valente was born in Entroncamento, a railway town 70 miles north of the country’s capital, Lisbon. 

He attended Agrupamento de Escolas Cidade do Entroncamento for lower secondary school before moving to Escola Secundária Maria Lamas in nearby Torres Novas.

Former teachers and acquaintances say he was a prodigy. At 17, he was selected for a national physics competition and went on to represent Portugal at the International Physics Olympiad in Canberra in 1995.

‘He was extraordinary,’ said one former teacher. ‘The kind of student you remember for life.’

That same year, Valente enrolled at Instituto Superior Técnico (IST), Lisbon’s most prestigious engineering school, to study Technological Physics Engineering.

Among his classmates was Loureiro. The course was small – about 45 students – and academically tough, bringing together some of the best young science students in the country.

According to Gonçalves, the president of IST’s Institute of Plasma and Nuclear Fusion, Valente quickly distinguished himself.

‘Claudio was known as the best student of his year,’ he said. ‘He graduated with 19 out of 20. It was exceptional.’ But there was no sense of rivalry at the time, Gonçalves said.

‘Of course, Claudio was the best,’ he said. ‘It was not even a competition. They had lectures together, but not the same practical groups. They were not directly competing.’

Another former professor at IST, Felipe Moura, remembered Valente as a negative and disruptive student in a Facebook post last week.

‘Claudio was obviously one of the best, but in class he had a great need to stand out and show that he was better than the rest,’ Moura wrote in Portuguese in the post.

‘Claudio’s attitude was unpleasant,’ he continued, often arguing with ‘colleagues he didn’t consider as brilliant as him (and who probably weren’t)’, he wrote. 

‘They were totally unnecessary quarrels, which did not help the class at all.’

Valente also worked as a student monitor at IST, reinforcing his reputation as an academic star.

Loureiro was a respected IST student but not seen as the standout of the group. Yet it was Loureiro who went on to build a highly successful international research career.

After graduating, Valente moved to the United States to begin a PhD in physics at Brown, but dropped out after about a year and returned to Portugal, reportedly disillusioned with the program.

Former classmates later recalled what they described as an eerie farewell message he sent at the time. He would later become estranged from his parents for more than two decades.

Valente worked intermittently between 2006 and 2013 as a computer scientist at Portuguese tech firm SAPO.

A former colleague told a Portuguese news outlet that Valente could be ‘kind and accessible,’ but said few people knew anything about his private life.

‘He was always a little strange,’ she said, ‘but we put that down to his intelligence. He could spend hours debating philosophy.’

But, she added: ‘While I confess there were other technicians who made me think, “one day this guy is going to grab a machine gun and wipe out all these people”, he didn’t give off that vibe.’

Valente left the tech company abruptly on two occasions. The last time a colleague spoke to him was in 2017 or 2018, when he said he was moving back to the United States.

Loureiro’s career took a very different path.

After completing his PhD at Imperial College London, he spent two years at Princeton University, then worked at the UK Atomic Energy Authority, now the Culham Centre for Fusion Energy, before returning to Lisbon to join IST’s plasma and nuclear fusion research unit.

Gonçalves said he worked closely with Loureiro in the UK around 2008 and 2009 and later became his colleague at IST.

‘That’s when I really got to know him,’ he said. ‘Nuno was extremely competent, extremely generous with his time, and very committed to his work.’

Loureiro remained at IST for six years before moving to MIT, cementing his reputation as a leading researcher in his field. He kept close ties with Portugal and regularly collaborated with former colleagues.

At the same time, Valente’s life appeared increasingly erratic.

In 2018, when he last renewed his Portuguese citizen card, he gave an address listed as an office building in Torrance, in Los Angeles County.

Police said his most recent official residence as a house in Miami but when a Daily Mail reporter visited the address last week, no one had any information about Valente.

In Lisbon’s Olivais district, where Valente lived while a student, neighbors recalled a quiet, aloof figure.

‘He was very intelligent, very educated,’ Margarida Baptista, who has lived in the building for more than 25 years, told the Daily Mail. 

‘But he was very reserved. It was always ‘good morning, good afternoon’ – nothing more.’

Asked why Valente might have targeted Loureiro, Gonçalves said he believed the motive lay not in any recent interaction but in what Loureiro had come to symbolize.

‘The strongest theory is that Claudio saw Nuno as a symbol of the academic and professional success that he himself had failed to achieve,’ he said.

‘It’s not a rivalry that existed at the time,’ he added.

‘It developed later. In the end, it may be jealousy, envy – someone that had a mental illness, seeing someone that achieved what you would like to achieve, and had the skills to achieve, but never made it. 

‘It’s a bitterness around probably his own decisions.’

Gonçalves said he did not believe IST or its academic culture was to blame.

‘The university provides a lot of psychological support,’ he said.

‘It was not the course. It was how Claudio chose to respond to the course.’

But he suggested the pressure of transitioning from elite academia into working life may have played a role.

‘It’s strange,’ he said, ‘that he didn’t just try to make something of himself in another field, like many IST students do.’

In Entroncamento, reaction was marked by shock and disbelief.

A family friend of Valente’s parents, who declined to be named, emerged from their home visibly upset and rejected media portrayals of him.

‘This family is so warm,’ she told the Daily Mail. ‘I don’t believe any of the reports we’ve seen on TV and in the news.’

She described Valente as ‘very charismatic’ and said the community was devastated.

‘I was on the train when I saw his picture on CNN Portugal,’ she said. ‘I burst into tears.’

She went on to suggest that Valente had not killed himself and may have been assassinated because of secret scientific work, repeatedly saying: ‘It’s not a coincidence.’

No evidence has been presented to support these claims but they underline the depth of disbelief among some who knew him.

Employees at MIT Plasma Science and Fusion Center told the Daily Mail they had been instructed not to talk to the media.

Loureiro’s mother is a French teacher and his father a former attorney in their native Viseu. 

His younger brother traveled to the US with their mother for the funeral, friends said. 

He had been due to fly to Madrid to meet his brother for a meal the day after he was shot, before traveling to Portugal for Christmas.