A sharp-eyed security team at Uber set in motion a nationwide criminal takedown after spotting a string of suspicious rides to banks involving elderly passengers — a tip that led the FBI to dismantle a ruthless “grandparent scam” ring accused of swindling $5 million from more than 400 victims.

Massachusetts U.S. Attorney Leah Foley said Tuesday the operation was a “cruel and malicious fraud scheme” run from call centers in the Dominican Republic, where scammers posed as panicked family members in desperate need of cash.

Alleged Mastermind and the International Web of Deceit

Authorities say accused ringleader Oscar Manuel Castanos Garcia orchestrated the racket, managing multiple call centers. Using voice-over-internet technology to mask overseas origins, his team allegedly mined victim lists from the dark web and often re-targeted the same seniors for repeat payouts.

“Their goal was to trick our parents, grandparents, neighbors and friends into handing over their life savings,” Foley said.

Twelve defendants are charged, including Castanos Garcia, who was arrested in the Dominican Republic. Prosecutors allege the ring relied on a U.S.-based network of “runners” who either collected cash in person or dispatched unsuspecting Uber and Lyft drivers to victims’ homes.

How the Scam Exploited Rideshare Platforms

In some cases, the fraudsters booked rides for supposed “family members” to take seniors to banks, enabling them to withdraw funds that were then funneled into U.S. business bank accounts.

Boston FBI Special Agent in Charge Ted Docks credited Uber’s global security and investigation team with detecting the pattern and alerting federal agents.

“This case exemplifies how Uber uses anti-fraud technology to swiftly detect and proactively report suspicious activity to law enforcement,” said Heather Childs, Uber’s chief ethics, compliance and security officer.

Guilty Pleas and Ongoing Trials

Two defendants have already been apprehended: Luis German Santos Burgos, accused of managing runners, pleaded guilty to conspiracy to commit mail and wire fraud and money laundering last month. Joan Manuel Mathilda Leon, an alleged accomplice, awaits trial.

Santos Burgos is represented by Jason G. Benzaken, Michael B. Homer, and Sara E. Silva. Mathilda Leon is represented by Tracy A. Miner. Castanos Garcia’s legal counsel was not immediately available.

The government is represented by David Holcomb of the U.S. Attorney’s Office for the District of Massachusetts.