WASHINGTON — Authorities have connected the dots between two harrowing incidents: the slaying of two students at Brown University and the murder of a Massachusetts Institute of Technology professor. Both crimes are believed to have been committed by a single individual who shares an academic link to these prestigious institutions.

The suspect, identified as 48-year-old Claudio Neves Valente, a former Brown University graduate student and a Portuguese national, was found deceased on Thursday evening, having apparently taken his own life. Providence Police Chief Col. Oscar Perez confirmed that Neves Valente is thought to have acted independently.

Officials suspect that Neves Valente was responsible for the deadly shooting that claimed the lives of two students and injured nine others in a Brown University lecture hall last Saturday. Just two days later, he allegedly killed MIT professor Nuno F.G. Loureiro at his residence in the Boston suburbs, situated nearly 50 miles from Providence.

Christina Paxson, President of Brown University, revealed that Neves Valente had been enrolled as a graduate student in the physics program from the fall of 2000 to the spring of 2001.

“He has no current affiliation with the university,” she said.

Federal investigators say Neves Valente and Loureiro shared an academic connection dating back to Portugal. U.S. Attorney for Massachusetts Leah B. Foley said the two attended the same academic program at a university of Portugal between 1995 and 2000.

Loureiro graduated in 2000 from the physics program at Instituto Superior Técnico, Portugal’s premier engineering school, according to his MIT faculty biography. That same year, Neves Valente was dismissed from a position at the Lisbon-based university, according to archived termination records issued by the school’s president in February 2000.

Authorities have not said whether that shared academic history played a role in the attacks. Rhode Island Attorney General Peter Neronha said investigators are still working to understand a motive.

There are still “a lot of unknowns” in regard to motive, Neronha said. “We don’t know why now, why Brown, why these students and why this classroom,” he said.

Loureiro joined MIT in 2016 and was named last year to lead the university’s Plasma Science and Fusion Center, one of its largest research laboratories. A physicist and fusion scientist from Viseu, Portugal, he was known for his work explaining the physics behind astronomical phenomena such as solar flares and advancing clean energy technology research.

Investigations into both shootings remain ongoing as authorities work to piece together the events and circumstances connecting the two attacks.

Law enforcement officials say an anonymous tipster known only as “John” helped crack the case. The tipster’s information led police to identify the suspect. 

According to police, John had several encounters with the suspect before Saturday’s attack. As police posted images of a person of interest John began posting on the social media forum Reddit that he recognized the person and theorized that police should look into “possibly a rental” grey Nissan. Reddit users urged him to tell the FBI, and John said he did. The police affidavit said they learned about the tip on Dec. 16, three days after the shooting and a day after the tip line was created.

Up until that point, the police affidavit says officials had not connected a vehicle to the possible shooter.

As of Thursday, it’s unknown whether John will receive the $50,000 reward the FBI had offered for information about the Brown shooting.

The Associated Press contributed to this report.