Maria Butina was the first Russian national convicted of seeking to influence American policy in the run-up to the 2016 election as an undeclared agent of a foreign government. (Press Service of Civic Chamber of the Russian Federation/EPA-EFE/Shutterstock)

U.S. prosecutors requested an 18-month prison sentence for Russian gun rights activist Maria Butina for conspiring with a senior Russian official to infiltrate the National Rifle Association and conservative U.S. political circles for the Kremlin from 2015 until her arrest in July.

Butina, 30, the first Russian national convicted of seeking to influence American policy in the run-up to the 2016 election as an undeclared agent of a foreign government, cooperated after pleading guilty in December, and prosecutors said their recommendation made Friday night had already accounted for a six-month reduction for cooperation under a plea deal.

While Butina was not a traditional spy or trained intelligence officer, her actions bore “all the hallmarks” of an intelligence operation to target powerful individuals in a future presidential administration for recruitment later, prosecutors wrote.

“The value of this information to the Russian Federation is immense,” they wrote, adding, “Such operations can cause great damage to our national security by giving covert agents access to our country and powerful individuals who can influence its direction.”

Butina faces sentencing in Washington set for April 26 before U.S. District Judge Tanya S. Chutkan of the District.

Her attorneys argued in their own Friday filing that she should be credited with the nine months served since her arrest, receive no additional imprisonment and be deported to her native Russia after the sentencing hearing.

Butina “has done everything she could to atone for her mistakes through cooperation and substantial assistance,” wrote attorneys Robert N. Driscoll and Alfred D. Carry. “Her remorse is genuine and deep.”

Butina cooperated fully and “answered all questions” since her plea, they added, including meeting voluntarily with the Senate Intelligence Committee.

Butina admitted to working under the direction of Alexander Torshin, a former Russian government official, and with an American political operative on a multiyear scheme to establish unofficial lines of communications with Americans who could influence U.S. politics.

Included in Butina’s filings to Chutkan were 19 letters attesting to her good character, 15 of which came from fellow Russians including family members, co-workers, her teachers and professors, and assault victims whom she helped when they were wrongly accused of crimes .

“If she violated something, it could not have possibly been intentional. The only possible reason that this could have occurred is lack of knowing the laws in the USA,” wrote Valeri Butin, Butina’s father .

One letter also came from George D. O’Neill Jr., a conservative American writer and Rockefeller heir who has acknowledged using Butina’s help to organize dinners of influential Russians and Americans advocating closer relations, said many of her dreams have “been crushed by political circumstances” outside her control.

“I write on behalf of Maria Butina, who I belie ve is a delightful and idealistic young soul,” O’Neill wrote, adding, “I hope , in sentencing her, the court would look at this lovely and able young woman and set her free without further punishment.”

The requests mark the approaching end of a prosecution that occurred against the backdrop of a “sweeping and systematic” campaign by the Russian government to influence the 2016 U.S. election, as laid out by special counsel Robert S. Mueller III in a report made public Thursday.

Although Butina spoke with Mueller investigators in post-plea debriefings, her case was unrelated to the probe and was prosecuted by the U.S. Attorney’s Office for the District of Columbia.

Her plan, which she called the “Diplomacy Project,” targeted the conservative movement and gun rights groups in particular as a way to reach the Republican winner of the 2016 election, who she correctly predicted would be Donald Trump.

Butina laid out the proposal in March 2015. Over the next two years, citing the NRA’s influence on the Republican Party, she traveled to conferences to associate with Republican presidential candidates, hosted “friendship dinners” with O’Neill and wealthy Americans, and organized a Russian delegation to attend the influential National Prayer Breakfast in Washington.

She gained access to these groups by founding a gun rights group in Russia and serving as an interpreter for Torshin, a lifetime member of the NRA as well as a former Russian senator and deputy governor of its central bank.

Capitalizing on her novelty as a Siberian-born gun activist in restrictive Russia, Butina and Torshin invited NRA leaders to Moscow in December 2015, including Milwaukee County Sheriff David Clarke and David Keene, a former NRA president and past head of the powerful American Conservative Union.

Butina stressed to Torshin the importance of setting up meetings with top Russian politicians, including a successful gathering with Russian Foreign Minister Sergei Lavrov.

Afterward, she wrote Torshin: “We should let them express their gratitude now, we will put pressure on them quietly later.”

Later, she wrote Torshin that “she had laid the groundwork for an unofficial channel of communication with the next U.S. administration.”

In sentencing papers, Butina’s lawyers said she never received Russian funding and was acting not under orders but out of genuine interest in improving U.S.-Russian relations.

“She did not seduce the figures within [the NRA] or funnel Russian money to it. Nor did anyone else instruct her to do so,” her defense said. Butina “asked Torshin — not the other way around — to set up meetings with Russian politicians to give an appearance of greater legitimacy for her group.”

Court documents indicate Butina worked closely with a Republican Party consultant with whom she had a romantic relationship after they met when he visited Moscow in 2013. He has been identified by government officials as Paul Erickson, a longtime GOP political adviser from South Dakota who managed the 1992 presidential campaign of Pat Buchanan.

Erickson was indicted in February in South Dakota over what federal prosecutors said was an unrelated investment fraud scheme.

Erickson’s attorney, William Hurd, has said his client is a “good American” who “has never done anything to hurt our country and never would.”

Rosalind S. Helderman contributed to this report.