On the evening of December 15, 2025, 47-year-old Portuguese physicist Nuno F.G. Loureiro was shot multiple times in the foyer of his apartment building on Gibbs Street in Brookline, Massachusetts. He was treated at the scene and taken to Beth Israel Deaconess Medical Center in Boston but died of his wounds early on December 16. Loureiro was the director of the Plasma Science and Fusion Center at MIT and was described as a respected academic; colleagues and students held vigils after the shooting.

The Norfolk District Attorney’s Office and the Brookline Police Department led the homicide investigation, recovering ballistic evidence at the scene. Forensic testing linked the firearm used in Loureiro’s killing to a mass shooting at Brown University in Providence on December 13 that left two students dead and nine others wounded. Investigators identified 48-year-old Cláudio Manuel Neves Valente as the connected suspect; he and Loureiro had attended Instituto Superior Técnico in Lisbon together in the late 1990s.

A multi-state manhunt ended when Valente was found dead of a self-inflicted gunshot wound in a Salem, New Hampshire storage unit on December 18, and ballistic testing confirmed the same weapon was used in both attacks. With the suspect deceased, no trial took place and the exact motive remains unexplained. Did anyone who knew Loureiro at Instituto Superior Técnico or MIT notice tensions that could explain why he was targeted?