*

Police seek public help with suspect's photo

*

Social media users speculate on weapon and escape route

*

Online sleuths' theories can mislead investigations

By Deborah Mary Sophia

Dec 5 (Reuters) - Zooming in on surveillance footage of

a gun that could have had a silencer fitted to it. Scouring the

web to identify the brand of a backpack. Triangulating data of a

rental bike to uncover an escape route.

Wednesday's shocking murder in Manhattan of UnitedHealthcare

CEO Brian Thompson - what police called a targeted

killing - brought out a bevy of sleuths and true-crime fans

across social media looking for clues about the killer's

motivation and how he managed to flee from the scene and

seemingly disappear into the city of more than 8 million people.

By Thursday, police were examining evidence ranging from

surveillance video to items discarded nearby that could contain

DNA to find the killer. Authorities also asked for the public's

help, releasing a photo with a clear view of his face.

Meanwhile, platforms including Bluesky, Reddit and X

sprouted hundreds of posts from amateur gumshoes poring over

video and photos. "Dude had a suppressor, which is an extremely

difficult thing to acquire, especially in a state like New

York," wrote one Reddit user.

Such forums are rife with so-called internet detectives who

pick through publicly available reports to uncover information

in the aftermath of major crimes. Sometimes, they succeed:

Online sleuths helped investigators identify numerous rioters

who took part in the U.S. Capitol riot on Jan. 6, 2021,

following Joe Biden's presidential election victory in 2020.

But such "crowd-sourced investigations" also can go awry.

Following the April 2013 Boston Marathon bombing, Reddit users

spread theories that pointed at the wrong people, which were

later amplified by publications including the New York Post. The

FBI released pictures of their leading suspects to quell the

speculation.

Social media helps people connect around a shared subject,

but it also blurs the line between news and speculation, said

Tahneer Oksman, a professor in Marymount Manhattan College's

communications department in New York.

"So many people are no longer making the important

distinctions between getting vetted information and

chatting/speculating about such vetted information," she said.

SCOURING THE INTERNET

A Reddit post about Thompson on the subreddit MorbidReality,

which has more than 1 million members, garnered over 260

comments. Users speculated the killer's weapon was a Station 6

pistol or an "exotic firearm called a B&T VP9." Others focused

on the backpack, calling it a "Peak Design Everyday Backpack

30L, Camera Bag."

On X, some users tried to chase leads on Citi Bike - New

York's bicycle rental system - for clues. One user posted

details about a bike that seemed to have been the only one that

left the area shortly after the shooting and headed toward

Central Park. Police later told media outlets they believe that

the killer likely used an unmarked e-bike, not a Citi Bike.

Early Thursday, users examined another crumb: reports that

the words "deny," "defend" and "depose" were carved into the

shell casings found at the scene. The words evoke the title of a

2010 book critical of the insurance industry titled "Delay Deny

Defend: Why Insurance Companies Don't Pay Claims and What You

Can Do About It."

Those comments set off more chatter about the shooter's

motivation, ranging from an early 2024 federal investigation

into the company to a lawsuit filed by a Florida pension fund

alleging insider trading.

Retired FBI agent Jennifer Coffindaffer on Thursday posted a

26-minute video on X laying out thoughts on the murder, saying

the killer knew exactly where Thompson would be and when. "That

just tells me there likely could be somebody on the inside,

somebody that knew when he would be leaving," she said.

Coffindaffer did not respond to attempts to contact her on X

or LinkedIn.