The New York Republican’s campaign treasurer Nancy Marks pleaded guilty Thursday to one count of conspiracy related to her oversight of the first-term congressman’s finances, and the New York Times reported that it’s clear prosecutors see a link between her criminal activity and Santos.

Santos was charged in May with 13 felonies in three unrelated financial schemes, and while Marks’ lawyer said she isn’t cooperating with investigators the lawmaker’s proximity to her criminal wrongdoing could leave him vulnerable to additional charges.

Prosecutors say Santos was “lost and desperate” at the end of 2021 after he failed to raise $250,000 in donations needed to be considered for a campaign committee program to aid his congressional race, so investigators said he and Marks agreed to file fictitious reports showing $50,000 in contributions from relatives who had not actually donated to make it appear he had met the threshold.