A longtime Brown University custodian has come forward with chilling revelations, claiming he spotted the suspected shooter lurking around the Barus and Holley engineering building nearly a dozen times over several weeks—and repeatedly flagged the suspicious behavior to campus security, only for nothing to be done.

Derek Lisi, a 15-year veteran custodian at the Ivy League school in Providence, Rhode Island, told investigators and media that he first noticed a man matching Claudio Manuel Neves Valente’s description in early November 2025. The 48-year-old Portuguese national, a former Brown student, allegedly opened fire in Room 166 on December 13 during a finals review session, killing sophomore Ella Cook and freshman Mukhammad Aziz Umurzokov while injuring nine others.

Lisi described the man pacing hallways, peering into classrooms—including the exact room targeted—and darting into bathrooms to avoid detection. “Every time he saw me, I think he thought I was security, because he would always walk away,” Lisi recalled. Believing the individual was “casing” the building, possibly to steal equipment, Lisi alerted a private security guard at least twice, once in mid-November and again in early December. He even followed the man once, only for him to evade confrontation.

Despite the reports, no action was taken. The security firm, a third-party contractor for events, later confirmed a December report but stated they do not handle investigations, typically deferring to Brown staff. Lisi, assuming his concerns were addressed, did not contact police directly until after the shooting, when released photos confirmed his fears: “I hope it’s not the guy I’ve been seeing.”

This wasn’t isolated; a faculty member reported a slow-driving rental car matching Valente’s around campus pre-attack, and another witness chased a suspicious figure hours before. Valente, found dead by self-inflicted gunshot in a New Hampshire storage unit on December 18, is also linked to the murder of MIT professor Nuno Loureiro—his former classmate—two days after the Brown incident.

The disclosures raise urgent questions about campus security protocols at Brown, where buildings like Barus and Holley have been described as accessible. In response, university president Christina Paxson announced immediate measures, including a rapid response team for safety enhancements ahead of the spring semester.

The tragedy has amplified debates on vigilance, response to suspicious activity, and resource allocation in higher education security. Lisi’s account underscores how frontline staff observations, if acted upon swiftly, might alter outcomes. As the community heals, his words serve as a somber call: potential threats cannot be overlooked.