Slain M.I.T. Professor Was a ‘Brilliant Scientist’ and a Beloved Colleague

 

Slain M.I.T. Professor Was a ‘Brilliant Scientist’ and a Beloved Colleague

 

Nuno Loureiro, 47, was killed by an old classmate who was on the run from a shooting at Brown University, the authorities said.

 

By Sarah MervoshAlexander Nazaryan and Azam Ahmed

Dec. 20, 2025, 5:02 a.m. ET

https://www.nytimes.com/2025/12/20/us/nuno-loureiro-mit-professor.html

 

Growing up in Portugal, when all of the other children dreamed of becoming a policeman or a fireman, Nuno Loureiro wanted to be a scientist.

 

And that he became, making startling discoveries in the world of physics while he was still in his 20s, achieving tenure by 40, and going on to lead a major research lab at the Massachusetts Institute of Technology.

 

“He was the kind of guy who went up to the chalkboard and started writing out equations and explaining everything,” said Bruno Gonçalves, director of the Institute for Plasmas and Nuclear Fusion at Instituto Superior Técnico, Portugal’s premier school for science and engineering, where Dr. Loureiro once worked as a researcher and team leader.

 

“The students loved it,” Dr. Gonçalves said. “He was like an Einstein without the crazy hair.”

 

Dr. Loureiro, 47, was fatally shot at his home in Brookline, Mass., this week, in a case that initially led to an outpouring of grief — and then shock, when the authorities announced that he had been killed by the suspect on the run from the shooting at Brown University two days earlier.

 

The suspect, identified as Claudio Neves Valente, walked into a study session at Brown University, in Providence R.I., on Dec. 13 and opened fire, killing two people and wounding nine others.

 

Two days later, the authorities said, he appeared in the tree-lined neighborhood of Brookline, where Dr. Loureiro lived with his family.

 

The authorities initially said the two cases did not appear to have a link, but in a dramatic turn on Thursday, they announced that Mr. Neves Valente was responsible for both shootings and that they had found him dead in a storage facility in New Hampshire. The authorities have offered no motive.

 

Deepening the mystery, the suspect and professor were both native Portuguese, around the same age and had both studied physics at Instituto Superior Técnico from 1995 to 2000.

 

But it was unclear how well the two knew each other then, how their paths may have crossed or whether they had been in touch in the decades since. Close friends of Dr. Loureiro said they had not heard of Mr. Neves Valente until the authorities announced his name as the suspect.

 

The developments have shaken the tight-knit world of nuclear science and physics, where Dr. Loureiro was seen as both a beloved figure and star.

 

Dr. Loureiro made his name as a 20-something, with a major breakthrough in understanding how the sun releases explosions of energy, a phenomenon seen in solar flares.

 

“It is rare that a Ph.D. thesis reorients an entire field of study, but it’s fair to say that Nuno’s work on magnetic reconnection did just that,” said Ellen Zweibel, a professor of astronomy and physics at the University of Wisconsin-Madison.

 

After earning his Ph.D. at Imperial College London in 2005, Dr. Loureiro conducted research at Princeton University and worked in the United Kingdom and Portugal, before heading to M.I.T. in 2016.

 

He was most recently leading the M.I.T. Plasma Science and Fusion Center. At the start of this year, he was one of nearly 400 people to receive the Presidential Early Career Award for Scientists and Engineers, the highest honor bestowed by the U.S. government on scientists and engineers at the start of their careers. Dennis Whyte, a former director of the Plasma Science and Fusion Center, described him as a “brilliant scientist” and a “brilliant person.”

 

Steven Cowley, the director of Princeton Plasma Physics Laboratory and a longtime friend and colleague of Dr. Loureiro, said that his friend had managed to solve a “50-year mystery” while still in his 20s, yet maintained a sense of humor and never thought too highly of himself.

 

“He would raise an eyebrow and look at you, and there would be a sense of irony,” said Dr. Cowley. “He had an eye for the absurd, and absolutely no pomposity. When he saw it in others, he thought it was funny.”

 

Far from the stereotypical scientist holed up in his lab with little to say to the outside world, Dr. Loureiro was known for being warm, down to earth — even stylish. In a profession full of jeans and T-shirts, he often wore round glasses and a nice jacket. He liked soccer and could often be found on the field with his daughter and children in his neighborhood.

 

“This picture of Nuno in everybody’s mind is always with this big toothy smile,” said Alexander Schekochihin, a professor of theoretical physics at the University of Oxford and a close friend. “When he came into the room, we all smiled as well.”

 

As a theoretical physicist and fusion scientist, Dr. Loureiro spent his days trying to untangle the mysteries of the universe.

 

Colleagues described him as a cherished mentor to students, known for making complicated theories come to life.

 

But to his three daughters, he was just Dad.

 

In explaining his job to his daughters when they were young, he said he spent his days “fighting numbers,” his family recalled in a obituary shared with The New York Times.

 

When his daughter asked, “how many numbers did you fight today?” he often replied: “Not as many as I would have liked.”

 

A small memorial, with flowers and candles, was accumulating on the steps to his home in Brookline on Friday. The M.I.T. campus was quiet, on a rainy December day at the end of the semester. Officials at the lab where Dr. Loureiro worked declined to comment, and students on campus said they had been directed not to talk to the media.

 

Many questions remained unanswered about why Mr. Neves Valente targeted Brown University, before showing up at Dr. Loureiro’s doorstep two days later.

 

Dr. Loureiro is survived by his wife, daughters, mother and a brother.

 

“He was completely devoted to his daughters,” said Dr. Cowley, who said that he saw his friend as recently as this month at a meeting in Washington. It was family, not physics, that they talked about first.

 

“This is the most tragic thing that I have ever known,” Dr. Cowley said. “For his wife and three daughters, it is devastating. You can’t imagine a person more unlikely to be hated by anybody.”

 

Daphné Anglès, Heather Beasley Doyle, James Glanz, Francesca Regalado and Pooja Salhotra contributed reporting.

 

Sarah Mervosh covers education for The Times, focusing on K-12 schools.

 

Azam Ahmed is international investigative correspondent for The Times. He has reported on Wall Street scandals, the War in Afghanistan and violence and corruption in Mexico, Central America and the Caribbean.