Federal prosecutors announced robbery charges Tuesday against five suspects accused of stealing more than $1 million from a jewelry store in the Bay Area suburbs — who were captured thanks to a secret GPS tracker hidden in one of the stolen watches.

The U.S. Attorney’s Office for the Northern District of California said the five suspects — Sunia Mafileo Faavesi, 30; Ryan Kentrell Montgomery, 35; Paul Christopher Tonga, 33; John Ioane Tupou, 30; and Kyle Vehikite, 34 — were charged with conspiracy to commit robbery for the theft from a San Ramon jewelry store in March.

Prosecutors said the suspects cased the jewelry store a week before the robbery on March 17. GPS data retrieved from one of the stolen Rolex watches helped authorities identify one of the suspects and piece together who the other co-conspirators were.

Four of the defendants, excluding Mr. Tupou, were arrested July 26.

The U.S. attorney’s office said a total of 11 suspects were involved in the heist at Heller Jewelers.

The robbers, some of them armed, made off with stolen watches and jewelry that was equivalent to $1.1 million in value. The suspects were inside the store for barely a minute before they linked up with getaway drivers outside the City Center Bishop Ranch mall and escaped.

Court documents obtained by the Mercury News indicated that the robbers may have been helped by a person who was a go-between for an informant inside a San Mateo County police department.

The go-between, who court documents suggested was a woman, told Mr. Tonga that information on the robbery investigation was “gon [sic] to cost you.” The unnamed woman appeared to provide periodic updates about law enforcement’s investigation.

If convicted, the suspects face up to 20 years in prison for the crimes.

• Matt Delaney can be reached at mdelaney@washingtontimes.com.