A custodian at Brown University has come forward with claims that he frequently encountered the suspect involved in the campus shooting well before the tragic event unfolded on December 13. He even went so far as to report his observations to a campus security officer.

Derek Lisi, speaking with The Boston Globe, recounted how he repeatedly spotted a man who appeared suspicious, pacing the corridors of the Barus and Holley engineering and physics building. This individual often peered into classrooms and, on one occasion, attempted to conceal himself in a bathroom to avoid detection. The incident on December 13 led to the deaths of two individuals and injuries to nine others, with five victims currently in stable condition at Rhode Island Hospital.

After police released images of the shooting suspect, Lisi immediately recognized the man, remarking, “He’d been casing that place for weeks.” The suspect has been identified by authorities as 48-year-old Claudio Manuel Neves Valente. According to Lisi, he had encountered Valente around ten times starting from early January.

Lisi’s account is accompanied by a photograph taken in Lincoln, Rhode Island, on December 21, 2025, showing him reflecting on the events. He expressed his unease, stating, “I knew there was something off with him.”

Derek Lisi, a Brown University custodian, is pictured in Lincoln, Rhode Island, on Dec. 21, 2025. He said he saw the alleged mass shooter on campus about 10 times in the weeks leading up to the attack. (Matthew J. Lee/The Boston Globe via Getty Images)

“I knew there was something off with him,” Lisi said.

In mid-November, Lisi told a security guard at Brown University that he saw the man “circling the hallways.” He said the man was consistently hanging around and peeking into room 166 at the building, where the eventual shooting took place. 

Ella Cook and Mukhammad Aziz Umurzokov were both killed in the shooting. Cook, 19, served as the vice president of the Brown University College Republicans.

A law enforcement official walks past articles of clothing on a sidewalk near an entrance to Brown University, Saturday, Dec. 13, 2025, in Providence, Rhode Island, during the shooting investigation. (Steven Senne/AP Photo)

Cook was laid to rest in Birmingham, Alabama, on Monday morning.

Brown University has also retained former U.S. Attorney for Rhode Island Zachary Cunha as it prepares for possible lawsuits.

“Brown works routinely with outside counsel whose expertise complements that of the University’s Office of the General Counsel. In this case, we retained Zachary Cunha, the former United States Attorney for the District of Rhode Island, to assist the University in coordinating with federal, state and local law enforcement agencies,” a Brown spokesperson said.

“I said, ‘Something’s off with this guy, so I gotta say something,’” Lisi recalled thinking when he saw the man on Dec. 1 before going on vacation. “I told my friend, ‘I hope it’s not the guy I’ve been seeing. I hope it’s not.’”

The shooting happened inside a classroom in the Barus and Holley engineering building around 4 p.m. Saturday, Dec. 13. Two students were killed, and nine students were wounded. (Gregory Norman-Diamond)

Lisi said he spoke with Providence Police on Dec. 15.

The custodian claimed that the Barus and Holley engineering and physics building has been “a free-for-all for a long time.”

“Anybody could just come in,” he added.

Fox News Digital reached out to Brown University for comment.