Police reports outline targeted Brookline killing of MIT professor Nuno Loureiro and suspect’s digital trail

Police narrative describes a rapid attack inside a Brookline entryway

Newly obtained Brookline Police reports provide a granular timeline of the Dec. 15, 2025 killing of MIT professor and laboratory director Nuno F. G. Loureiro, 47, who was shot inside the shared foyer of his Gibbs Street home in what investigators characterized as a swift, targeted assault.

Officers were dispatched at about 8:33 p.m. for reports of gunfire. Loureiro was found suffering from multiple gunshot wounds and was transported to Beth Israel Deaconess Medical Center, where he was pronounced dead early the next morning, at 5:50 a.m., police records state. Investigators recovered multiple 9mm shell casings, bullet fragments, and evidence of ballistic strikes in the foyer and stairwell.

A child’s account and a distinctive disguise

One of the most detailed early descriptions of the assailant came from Loureiro’s 12-year-old daughter, who told police she briefly opened the apartment door before her father intervened. In her account, a man stood in the vestibule wearing a yellow reflective vest over dark blue clothing and a winter hat, carrying what appeared to be a square cardboard package. She described the man as between about 5-foot-8 and 6 feet tall, with a medium build, and said he fled to the driver’s side of a blue or gray Nissan sedan that sped away toward Stedman Street.

Police noted the building entrance did not have security cameras, increasing reliance on surrounding surveillance systems and witness statements.

Surveillance footage maps movements before and after the shooting

A neighborhood video canvass documented a lengthy presence in the area earlier that day. Footage reviewed by investigators showed a masked individual wearing glasses moving along Commonwealth Avenue in the early afternoon and entering multiple businesses, including a restaurant where food was purchased with cash.

Police also documented a gray Nissan Sentra parked nearby as early as the morning hours. Minutes before the shooting, a camera near the intersection of Gibbs Street and Naples Road recorded a person in a reflective vest in the area. After the gunfire, additional video sources—ranging from nearby institutional systems to transit-related cameras—captured a Nissan departing with headlights off and traveling west through multiple communities.

Case tied to a separate Brown University shooting

Authorities later linked Loureiro’s killing to the Dec. 13, 2025 mass shooting at Brown University that killed two students and wounded others. Law enforcement identified 48-year-old Portuguese national Claudio Manuel Neves Valente as the suspect in both incidents.

Federal authorities said Neves Valente and Loureiro had overlapping academic history in Portugal in the late 1990s. Neves Valente was later found dead of an apparent self-inflicted gunshot wound in a New Hampshire storage facility as the multi-agency manhunt closed in.

Investigation scope and unresolved motive

The homicide investigation drew regional and federal participation, including state police, prosecutors, and federal agents. Detectives interviewed colleagues at MIT’s Plasma Science and Fusion Center and examined whether any professional disputes or university processes could be relevant, while noting that a clear motive had not been established in the police documentation.

• Evidence collected included ballistic material, bloodied items used in attempted first aid, and extensive surveillance video.
• Investigators cataloged large volumes of digital and forensic documentation as the case expanded beyond Brookline.

Police records depict a methodical effort to reconstruct the suspect’s movements through synchronized video, witness accounts, and physical evidence, while the underlying motive remained under investigation.