The killing has triggered a multi-agency homicide investigation and shocked the U.S. scientific community.

Loureiro, 47, was a senior figure in U.S. plasma and fusion research and had led one of MIT’s largest laboratories since 2024.

Authorities have disclosed few details, and no suspect or motive has been identified.

Shooting and Investigation Timeline

Brookline police responded to reports of gunfire at an apartment building on Gibbs Street between 8:30 and 9:00 p.m. on December 15.

Neighbors reported hearing multiple loud bangs, initially mistaking them for other noises, before emergency services were called.

Loureiro was found wounded near the building’s entrance, with his wife and neighbors placing 911 calls.

He had been shot multiple times and was transported to a nearby hospital, where he was pronounced dead on the morning of December 16.

The Norfolk County District Attorney’s Office is leading the investigation alongside Brookline Police, Massachusetts State Police, and MIT Police, which confirmed the case is being treated as a homicide.

Authorities have said no suspect has been identified or taken into custody. I

nvestigators also stated there is no known connection between Loureiro’s killing and other recent campus-related shootings, including an incident at Brown University, and no public determination of motive has been made.

A Leading Figure in Fusion Science

Born in 1977 in Viseu, Portugal, Loureiro earned his undergraduate degree in physics from Instituto Superior Técnico in Lisbon in 2000 and completed his PhD at Imperial College London in 2005.

He later held postdoctoral positions at the Princeton Plasma Physics Laboratory and the UKAEA Culham Centre for Fusion Energy.

He joined MIT’s faculty in 2016 and rose rapidly through the academic ranks.

In May 2024, he was appointed director of MIT’s Plasma Science and Fusion Center (PSFC), overseeing one of the institute’s largest research operations focused on plasma physics and fusion energy.

His research addressed plasma dynamics, magnetic reconnection, and turbulence in magnetized plasmas, with applications ranging from fusion reactors to astrophysics and space physics.

Institutional and Community Response

Loureiro received numerous professional honors, including the American Physical Society’s Thomas H. Stix Award, an NSF Career Award, election as a Fellow of the APS in 2022, and a Presidential Early Career Award for Scientists and Engineers in January 2025.

MIT President Sally Kornbluth described his death as a “shocking loss,” while tributes also came from the U.S. Ambassador to Portugal and colleagues across the international scientific community.

He was married, had children attending local schools, and was described by neighbors as an engaged and supportive member of the community.

MIT said it is providing support services to students, faculty, and staff affected by the killing.

Some reports from Jewish media outlets characterized Loureiro as Jewish and pro-Israel.