PHILADELPHIA -- As he posted a collection of images he shot during the protests that gripped Philadelphia after the police killing of George Floyd, Sammy Rivera beseeched his Instagram followers to be careful of what they shared online.
"Photos and video footage of the protests were used to pick out protesters who were then identified and tracked down via their online/social media presence," he wrote in the caption to his June 26 post that warned just "how easy it could potentially be for others to be tracked down and arrested or worse."
Five weeks later, Rivera himself was placed in handcuffs, accused in a case built in part on the photos he shared in that post.
The 23-year-old Port Richmond resident was one of six men charged this week with vandalizing two Pennsylvania State Police squad cars May 30, during the first day of unrest that erupted in Center City. Each of them was identified at least in part by postings or associations on their public profiles on platforms like Facebook and Instagram.
Their cases highlight the extent to which the very same social media content that has fueled demonstrations across the country and aided the prosecutions of officers charged with police brutality -- including the viral video that led to charges against the cops accused in Floyd's death -- has become a primary resource for law enforcement seeking to track down those responsible for looting and violence.
In investigating the destruction of the State Police squad cars, investigators had little to go on at first but a cache of still photos the FBI obtained from a University of Pennsylvania student who documented much of the unrest that erupted May 30, according to search warrant and arrest affidavits obtained by The Inquirer.
(A photo collection from an amateur photographer and social media cross-referencing also helped federal agents identify Lore-Elisabeth Blumenthal, a Germantown massage therapist who was federally charged June 15 with setting two Philadelphia police cars ablaze outside City Hall that same day, court filings in her case show.)
The FBI used a Philly protester's Etsy profile, LinkedIn and other internet history to charge her with setting police cars ablaze. The Penn student's photos depicted a crowd surrounding the State Police vehicles, which were parked on the onramp to I-676 near Broad Street to block protesters from marching onto the highway. Demonstrators captured in the images battered the cars with scooters, a hammer, skateboards, a bike lock, crowbars and their hands and fists before breaking into the vehicles and setting one of them on fire with state-issued road flares stolen from inside, the affidavits say.
Several photos showed a masked man in a black T-shirt, gray shorts and backward baseball cap repeatedly kicking the driver's side door of one of the cars. In one of the images, other protesters are seen trying to restrain the man to prevent him from causing further damage.
A distinctive facial tattoo of a cross near the man's right eye and others on his wrists and forearms that allowed state police to ID him as Luke Cossman, 20, of Levittown, using PennDOT facial recognition software -- a match that was later confirmed through photos of himself at the protests that he publicly posted to Facebook.