Catalytic converter thefts in Massachusetts have been on a “precipitous decline” after the feds took down a “skilled, organized theft crew” that stole from nearly 500 vehicles as it looked to score big on the precious metals.

There’ve been only seven reported incidents of catalytic converter thefts across the Bay State over the past 11 months since a collaboration between federal, state, and local law enforcement arrested the seven-member crew last April, according to court filings.

Carlos Fonseca, 33, of Springfield, became the sixth member to plead guilty to his role in the thefts when he appeared in federal court in Boston on Monday. He was arrested on charges of conspiracy to transport stolen property in interstate commerce and interstate transportation of stolen property.

Judge Leo T. Sorokin has scheduled Fonseca’s sentencing for June 21. The crew’s alleged leader Rafael Davila has pleaded not guilty and remains pending trial, according to the feds.

Before the operation was taken down April 12, 2023, there were “hundreds of thefts reported during the nine-month period prior,” the feds said in a release Tuesday.

The crew stole catalytic converters from at least 496 vehicles across Massachusetts and New Hampshire between 2022 and the time of their arrests, the culmination of “Operation Cut and Run,” a joint effort by federal law enforcement agencies, the Massachusetts State Police, and more than 70 local police departments in Massachusetts, New Hampshire and Connecticut.

Fonseca, specifically, stole catalytic converters from 103 vehicles in 13 separate instances between Aug. 23, 2022 and Oct. 4, 2022, most of which targeted vehicles in multiple cities and towns in a single night.

“The thefts resulted in losses of approximately $5,000 per vehicle with certain trucks costing over $10,000 to repair,” prosecutors said. “This amounts to an approximate $2 million in losses suffered by more than 300 separate victims who were forced to deal with their vehicles being disabled for potentially weeks on end.”