Lisi, who has not been identified publicly until now, said he had seen a man matching the description and photos of the suspect, shared by the police, in and around Brown’s Barus and Holley building about 10 times beginning in early November.
“I knew there was something off with him,” Lisi said.
Twice, Lisi said, he told a campus security guard about a suspicious person in the engineering and physics building.
Get Rhode Island News Alerts
Event Staffing Services, a contractor that works at Brown events, confirmed a custodian told one of its employees about a suspicious person in the building in December, but said it doesn’t investigate reports like that.
Lisi said that, in mid-November, he told someone, who he believed was an ESS staff member working as a security guard that he had seen a man “circling the hallways.”
Brown officials didn’t respond to requests for comment.
Lisi said he continued seeing the man peering into classrooms and hanging around outside Room 166 in particular.
“I thought it was someone trying to steal something,” Lisi said. “Every time he saw me, I think he thought I was security, because he would always walk away.”
It was in Room 166 that the suspect, identified by police as Claudio Manuel Neves Valente, allegedly opened fire, killing two people — students Ella Cook and MukhammadAziz Umurzokov — and injuring nine others.
Police also linked him to the murder two days later of MIT professor Nuno F.G. Loureiro in Brookline.
Lisi said his suspicions about the man in the building grew in early December. Once, Lisi said, he decided to follow the man after seeing him in a parking lot.
When the man saw him, Lisi said, the man started walking away quickly and ducked into the bathroom.
“I said, ‘Something’s off with this guy, so I gotta say something,’” he recalls.
He flagged down the same staff member again. According to Lisi, the person didn’t investigate. ESS the private contractor, said it doesn’t investigate reports and focuses narrowly on overseeing events, including on-campus gatherings and sports games.
Lisi said he didn’t contact police either, believing he had flagged the issue appropriately, and simply went back to his custodial work.
Providence police confirmed Lisi told them after the shootings that he had earlier alerted a security guard.
ESS, the private contractor, said its role on campus does not include investigating reports of suspicious people or other similar concerns.
“We have nothing to do with watching buildings,” said David Madonna, ESS’ president, in an interview Monday. “Whenever there’s an event at Brown, they hire us to do ID check and capacity counts in their rooms.”
Madonna said he spoke with a staffer who recalls talking with a custodian about a suspicious person in the building in early December. He said he didn’t know of any similar reports from November.
Either way, Madonna said the company’s staff do not perform the duties of a security guard, they don’t carry any weapons, and that when public safety issues arise, they don’t typically call campus police but will tell Brown staff to do so. He said that’s what his staff member did that day in December, as well.
Lisi on Monday said he believed he was speaking to security guards when he reported someone acting strangely, and that the patchwork of third-party firms at Brown can be confusing. He said he couldn’t remember if the staffer told him to call the police.
Lisi was not the only person to have gotten a glimpse of the alleged assailant before the mass shooting.
A man identified by police only as “John” also told police he had seen the suspect acting suspiciously near the building in the days leading up to the attack and at one point in the hours before the shooting had allegedly chased him on foot.
Police say that tip, first flagged on the social media site Reddit, led them to a rental car, and ultimately to New Hampshire, where the suspect was found dead of a self-inflicted gunshot.
There have been calls for “John,” the Reddit user, to be given the promised $50,000 reward offered by the FBI.
On Dec. 13, when Lisi got an alert about a shooter on campus sent to members of the Brown community, he said he immediately thought of the suspicious man he’d seen in the building.
“I told my friend, ‘I hope it’s not the guy I’ve been seeing. I hope it’s not,’” he said.
Then he saw images of the suspect, he said. He recognized him right away.
“I knew it was him because I could tell by the walk,” he said. “He had a pretty distinctive walk.”
Lisi said he also recognized the jacket and dark clothing he wore. The only difference was that he remembered seeing him in a blue face mask, not a black one.
He called a tip line that night and told police to look for security footage on two days in particular, when he was certain he had seen him. Police met with him two days later, he said.
Two days later, on Monday night, police called and asked to meet with him, and they spoke in a Home Depot parking lot, he said.
In an affidavit, police said they spoke with a man, who they later confirmed is Lisi, who said he had run-ins with a man matching the shooting suspect’s description.
Police also confirmed that, at the time, Lisi told them he had previously flagged the suspicious person to campus security personnel.
Lisi said he contacted police long before the FBI began offering a reward for information connected to the case, and said he is interested in student safety, not the money.
“I just did it for the safety of the students. That’s primarily what I care about,” he said. “It’s about making sure that they learn from this and that it doesn’t happen again,” he said.
Lisi said he hopes the tragedy leads to new safety restrictions in buildings like that one, which he described as “a free-for-all” where “anybody could just come in.”
Lisi said he is close with people who work and study in the building. One, a PhD student named Alec McCall, said Lisi has a friendly presence and has always been concerned about the welfare of students.
“He just cares about everyone,” McCall said.
Lisi said it still eats at him that he repeatedly crossed paths with an alleged shooter who had been lurking in the hallways undetected for weeks.
“I just wish there was something I could have done,” Lisi said.
Steph Machado of the Globe Staff contributed to this report.
Spencer Buell can be reached at [email protected]. Follow him @SpencerBuell.
