How surveillance technology and the ‘Reddit Detective Agency’ helped search for a killer

A makeshift memorial is seen on the campus of Brown University, close to from the scene of the shooting, Monday, Dec. 15, 2025, in Providence, R.I. (AP Photo/Robert F. Bukaty)

PROVIDENCE, R.I. — More than a decade ago, a frenzied 5-day search for the Boston Marathon bombers left some lessons in its aftermath.

One was that increasingly pervasive surveillance technology could help catch the culprits. Another was that amateur online sleuths on Reddit could not.

But the intense search this week for a suspect in a Brown University shooting that killed two students and wounded nine other people turned the tables on those expectations.

Sweeping surveillance, now found in doorbells, cars and a vast network of vehicle-tracking cameras, did eventually help track down the whereabouts of Claudio Neves Valente, the 48-year-old former Brown graduate student investigators believe was responsible for the Dec. 13 shooting and another killing two days later of an MIT professor in Brookline, Massachusetts.

But the latest artificial intelligence-powered surveillance was of little use in the early search for a gunman who walked away from the Brown campus after the shooting and slipped unnoticed into the surrounding neighborhoods of Providence, Rhode Island. He evaded detection for days, using a hard-to-trace phone, avoiding facial recognition software by obscuring his face with a medical-type mask and switching the license plates on his rental cars.

It wasn’t until a local Reddit user “blew this case right open” with an old-fashioned tip first posted on the social media platform that police were able to connect a car to Neves Valente, said Rhode Island Attorney General Peter Neronha. They finally found the suspect dead Thursday in Salem, New Hampshire, days after he likely killed himself.

The Reddit tipster known only as John is “no less than a hero,” Providence Mayor Brett Smiley wrote Friday to FBI Director Kash Patel, asking for John to get the entirety of the FBI’s US$50,000 reward for information leading investigators to the suspect.

Strangers have invited him to Christmas dinner and suggested he get a “key to the city and free coffee and doughnuts for life,” according to fellow contributors to Reddit’s Providence forum.

It was a stark turn from 2013 when commentators on Reddit and other online discussion boards falsely smeared a Brown University student as a potential suspect in the deadly attack at Boston’s famed marathon, just an hour north of Providence, because of a supposed resemblance to a grainy suspect image.

“Hey Reddit, enough Boston bombing vigilantism,” declared a headline in The Atlantic at the time.

“It definitely went sideways in the Boston Marathon situation,” said Liza Potts, a professor at Michigan State University and director of a digital humanities lab that studied the online response. “That’s why folks will jokingly refer to the ‘Reddit Detective Agency’ or the ‘Reddit Bureau of Investigations.’”

The mistaken connection between the 2013 bombers and a missing Brown student — who was later found dead of an apparent suicide — is still remembered by many at the Ivy League school and its surrounding community.

Brown officials this week sought to swiftly tamp down another smear campaign circulating on X and other social media platforms falsely tying a current Brown student to the campus shooting because of his ethnicity, perceived political views and supposed resemblance to a police video of a person of interest. The “unimaginable nightmare” of false accusations led to “non-stop death threats and hate speech,” the student said in a statement.

Frustrated that tip lines could be jammed with nonsense, U.S. Sen. Sheldon Whitehouse, a Rhode Island Democrat and former state attorney general, urged social media speculators to “just shut up.”

“There is simply no need from an investigative point of view for people who have no idea what they’re talking about to offer their stupid and ill-informed views about what happened all over the internet,” Whitehouse said from Congress on Wednesday.

But Potts said some social media has been working better than others, and “of all the spaces that I study, Reddit seems to be getting it right more than not.”

Harmful accusations were largely absent from Reddit’s Providence forum, in part because volunteer moderators who manage Reddit’s subject matter forums — known as subreddits — are largely responsible for keeping the peace.

Reddit’s chief moderator for the Providence subreddit said in an interview that he’s been on the platform for about 15 years and remembers the trauma that false Boston Marathon report caused.

“The Providence subreddit is very sensitive about (not) trying to go on a witch hunt or the mob mentality,” he said, speaking on condition of anonymity to avoid doxing and because of the platform’s culture of anonymity.

The Associated Press also reached out to the tipster on Tuesday, a day after he wrote on Reddit urging police to look into a Nissan sedan with Florida license plates. Fellow Redditors urged him to contact the FBI, and he said he did.

He didn’t respond to requests for comment and later posted that he doesn’t plan to talk with media. When he finally met with police on Wednesday — after approaching them on the street and identifying himself as the Reddit tipster — his information gave new life to a stalled investigation.

With a known vehicle, Providence police started looking through the footage from dozens of AI-powered cameras positioned around the city that can read license plates as well as other identifying details about a car, such as make, color, side damage or even bird droppings on the window.

The cameras, run by surveillance company Flock Safety, spotted his vehicle at least 14 times starting nearly two weeks before the shooting, according to a police affidavit. Providence police could then ask Flock-using police agencies in nearby cities and states to look for the same car, although New Hampshire — because of privacy restrictions on how long they can hold images — doesn’t have any.

It was a breakthrough Flock was happy to boast about, especially as wariness remains in Providence’s immigrant communities about more aggressive federal immigration enforcement. Flock says each of its customers decides when to share camera data, and the city doesn’t share it with federal immigration agents. Some still want more safeguards.

“Once you know what they are, you see them everywhere,” said Madalyn McGunagle, a policy associate at the ACLU of Rhode Island. “People notice because they’re distinct-looking — a solar panel on top with a little oval camera underneath.”

But unlike the residential doorbell cameras that spotted him walking around Providence, had Neves Valente walked by a Flock camera, it wouldn’t have detected him, said Flock Safety CEO Garrett Langley.

“It is a technical impossibility. The camera does not have an ability for a user to search for people,” Langley said in an interview Friday. “Our cameras are focused on vehicles because if you look at America, people drive. It is very hard to get anywhere on foot.”

“For the majority of our cities, they want to just know who is coming in and who is leaving,” he said.

Still, without John the tipster — whom local Redditors dubbed “Reddit Guy” — no one would have known how he left.

“Someone who is in the area and sees stuff all the time, they’re going to be better in a lot of ways than a random camera,” said the Providence subreddit’s moderator. “John saw this guy going back and forth, unlocking his car and all that, and he just thought it was kind of weird.”

Matt O’brien, The Associated Press