Updated December 19, 2025 at 1:36 PM EST
A Reddit post by an observant witness helped lead investigators to the gunman officials say was responsible for the killing of two students during the shooting at Brown University on Saturday and for the fatal shooting of an MIT physics professor two days later.
That's according to an affidavit from the Providence Police Department.
Brown students Ella Cook, 19, and Mukhammad Aziz Umurzokov, 18, were killed and nine were injured in the attack on Saturday at the school. MIT physics professor Nuno F.G. Loureiro was killed at his home in Brookline, Massachusetts, about 50 miles away from the site of the mass shooting in Providence, on Monday.
Earlier this week, law enforcement tracked Valente to a Salem, New Hampshire, storage unit where he was discovered dead.
"While we'll never be able to prosecute this individual, I hope this result begins to provide some small measure of closure for the victims and their families," said Rhode Island Attorney General Peter Neronha.
Here's what we know:
The suspect had ties to Brown University and slain MIT professor
Police say Claudio Manuel Neves Valente, 48, is the man responsible for the two attacks in New England.
He was born in Torres Novas, Santarem, Portugal and was a legal permanent resident of the United States. Valente arrived in the country in August 2000 as a graduate student at Brown under an F-1 visa, which is reserved for international students to attend colleges or universities full-time in the U.S.
Leah Foley, the U.S. attorney for the District of Massachusetts, said at a news conference on Thursday that Valente and Loureiro, the slain MIT professor, attended the same academic program between 1995 and 2000 at a university in Portugal.
Valente was enrolled in Brown's PhD physics program from fall 2000 until the spring 2001 semester, after which he took a leave of absence. He officially withdrew in the fall of 2003, according to the affidavit.
F-1 visa recipients are required to return home after their studies. But in May 2017, Valente received a "diversity immigrant visa" from the U.S. That September, he was admitted to the country as a legal permanent resident at JFK International Airport in New York, according to the affidavit from the Providence Police Department.
The Diversity Immigrant Visa Program, suspended by the Trump administration in the wake of these shootings, usually makes around 50,000 green cards available each year by lottery to people from countries that have low rates of immigration to the U.S.
Police say Valente's last known address was in Miami. It's unclear what happened during Valente's life or what he was doing from 2017 until the days leading up to the shootings.
Reddit post was the key breakthrough
According to the affidavit, three days after the shooting, on Dec. 16, investigators received information from an anonymous source that said there was a Reddit post in the Providence sub-Reddit referencing details about the shooting. At the time, police had only released surveillance images of the suspect.
This Reddit post became a key breakthrough in the case, according to Neronha, Rhode Island's attorney general.
This post, written by a witness, said they saw the suspect, later identified as Valente, walking in the area of Brown before the shooting. The post read, "The police need to look into a grey Nissan with Florida plates, possibly a rental. That was the car he was driving."
The post goes on to describe that the car was parked behind the Rhode Island Historical Society on Cooke Street in the city – near the Brown University campus.
Police are calling this witness "John." And on Dec. 17, John approached Providence police officers and described his unusual encounter with Valente before the shooting at Brown, according to the affidavit.
Reddit poster 'John' had interactions with the suspect
In the affidavit, investigators say John recounted first seeing Valente in a bathroom inside Brown's Barus Holley building about two hours before the shooting Saturday.
John described Valente's clothing as "flimsy," "poor quality" and "inappropriate and inadequate" for the weather at the time, according to the affidavit. He also told police that Valente was wearing a face mask that covered the entire lower half of his face.
He then encountered Valente again around the Rhode Island Historical Society and witnessed the gunman approach a gray Nissan with Florida plates parked by the building.
John said a game of "cat and mouse" began with Valente as he continued to follow him.
According to the affidavit, John confronted Valente and Valente responded, saying, "I don't know you from nobody. Why are you harassing me?"
Eventually John continued on his way.
This is a developing story.
Copyright 2025 NPR
