Three men have been arrested in connection with a string of robberies at the Carquinez Bridge toll plaza, California Highway Patrol officials announced Thursday morning.

The suspects were identified by the CHP as Vallejo residents Robert Larry White, 43; Christopher Lee Miller, 30; and David Joseph Morales, 47, who was already in custody on unrelated charges.

The maximum sentence faced is a potential 31 years for Miller. 

CHP officials said at a news conference Thursday morning that the suspects have been linked to three of 10 robberies of toll-takers that occurred between late 2011 and May 2012.

"I think it was a crime of opportunity," explained CHP lead investigator Matt Werle. "That's the best way I can describe it."

In the robberies, suspects would drive up to the toll plaza and demand cash from the toll-takers. The perpetrators often wore ski masks and were armed with various weapons, which they used to threaten their victims, Werle said.

He said the robbers used stolen cars to commit the crimes. At least two of those vehicles have been recovered.

Werle said he figured out who the suspects were back in August and starting searching for them about a month ago.

Miller was arrested a week ago in Fairfield, while White was arrested during a traffic stop in Vallejo Wednesday.

Investigators credited other agencies for helping crack the case. Napa County authorities found evidence of the Carquinez robberies while serving search warrants in a different investigation. .

"During our search warrants on those residences, we found evidence linking them to several crimes in several different counties," said Napa County Sheriff's Dept. Captain Tracy Stuart.

Benicia police provided intelligence also gathered when the suspects' associates rolled through that town.

Werle said CHP investigators believe there are other robbery suspects still at large, and that the investigation into the robberies is continuing.

All three men in custody are Vallejo natives with criminal histories, CHP officials said Thursday morning. Werle said it is not yet clear whether they know each other.