Twelve Russian intelligence officers have been charged with hacking the emails of the Democratic National Committee in one of the most significant developments of the Russia investigation to date.

The charges were announced on Friday by Deputy Attorney General Rod Rosenstein. The DNC hack was one of the major prongs of the Russian interference in the 2016 election, with the emails leaked to the internet in an effort to damage Hillary Clinton’s chances of winning and boost Donald Trump.

Grand jury turned in an indictment charging the 12 Russian military officers with conspiring to interfere with the 2016 presidential election. They are charged with infiltrating computers including state boards of election, secretaries of state, and companies that provide software to monitor elections.

The officers worked for two units of Russian intelligence, one that engaged in active cyber operations by stealing information and another that disseminated the information, Rosenstein announced. They used a scheme known as “spearfishing” which tricked users into disclosing their information that allowed hackers to gain access to emails. They also hacked into networks and installed malicious software that captured keystrokes, took screenshots, and allowed them to take data from the computers.

The groups created the online personas DC Leaks and Guccifer 2.0 used to release the stolen emails, claiming that DC Leaks was a group of American hackers and Guccifer 2.0 was a lone hacker, but Rosenstein said both actually worked for Russian intelligence.

“The groups used a worldwide network of computers to hide their activity, paying for it using cryptocurrency,” Rosenstein added.

The Russia investigation has now led to charges against 32 people, including previous charges against 14 Russian nationals for their work on spreading Russian-based propaganda. Three Russian companies have also been charged, along with top Trump advisers Paul Manafort and Michael Flynn. The current indictment did not allege that any Americans committed crimes related to the Russian hacking, Rosenstein announced.

In his Friday announcement, Rosenstein called for an end to partisan fighting over the Russia investigation, just one day after a Congressional panel grilled the former FBI agent Peter Strozk over his private text messages that were critical of Donald Trump.

“It’s important not to think as Republicans or Democrats, but patriotically as Americans,” he said.

Mueller probe indicts 12 Russian intelligence officers for allegedly hacking the Democratic National Committee https://t.co/AZE4wPVRCA — The Wall Street Journal (@WSJ) July 13, 2018

The announcement came just before President Donald Trump is set to meet with Russian President Vladimir Putin in Helsinki. Rosenstein said that Trump had already been briefed on the indictments earlier in the week.