Charles “Joe” Hynes was the district attorney of Kings County, New York. Photo Credit: AP

Former Brooklyn District Attorney Charles “Joe” Hynes has agreed to pay a $40,000 fine for improper use of his official email account during his failed 2013 run for a seventh term in office.

Hynes' payment of the fine is part of a settlement agreement reached with the New York City Conflicts of Interest Board, which announced on Tuesday that Hynes used his official email account with the Brooklyn District Attorney's Office to send more than 5,000 campaign-related emails during his primary battle against Kenneth Thompson.

Thompson withstood both a primary and general election challenge from Hynes and served as Brooklyn DA from 2014 to 2016 before resigning to battle cancer. Thompson died days after his resignation.

In a public statement from Walden Macht & Haran, which represented Hynes in the case, Hynes said he mistakenly used his government email account to send campaign-related emails “in the midst of a “feverishly contested primary race.”

In addition to Hynes, three former Brooklyn DA staffers and a current assistant DA who previously served as counsel to Hynes were fined a combined $14,500 for also using their government email accounts to send messages about Hynes' re-election bid.

But Hynes, whose long tenure as Brooklyn DA began in 1990, said in the release that he should take the heat for the actions of his former subordinates.

“If anyone is to blame for this, it should be me and me alone,” Hynes said. “I hope my decision to resolve the matter early causes the COIB to leave my former staff alone, they did nothing wrong and they served the public good doggedly every day they came to work.”

Jim Walden of Walden Macht appeared for Hynes.