A local historian preparing to author a book on the Cold War says the federal government is blocking her from accessing more than a thousand documents about a criminal investigation that led to her mother's conviction as a Soviet Union spy.

Frustrated from years of receiving heavily redacted documents, and in some cases no documents at all, Emily Socolov filed a lawsuit Monday in Austin asking a federal judge to step in and order the U.S. Department of Justice to produce records she says could be critical to her book on the Red Scare in 1950s America. She is a visiting scholar at the University of Texas.

The records, according to the lawsuit, will help show how the FBI built a case that led to the 1949 arrest of Socolov's mother, Judith Coplon, a 27-year-old political analyst for the Justice Department. The government suspected she was working in counterintelligence for the Soviets. After intercepting a secret Soviet cable in 1948 that identified Coplon by a code-name, federal agents set up a sting operation by feeding her a false memorandum about atomic power. Tracking her movements around Manhattan, the feds caught Coplon meeting with Soviet agent Valentin Gubitchev and arrested them both. Several documents, including the faked memo, were found on Coplon.

Convicted at separate trials for espionage and for conspiracy, Coplon eventually prevailed on appeal — in one case because federal agents overheard conversations with her lawyer, and in the other because she was arrested without a warrant — and avoided a 25-year prison sentence.

According to her 2011 obituary in The New York Times, Coplon went on to marry one of her lawyers, raised four children and earned a master's degree in education. She died at 89 as Judith Socolov, leaving behind questions about her innocence or guilt — a topic she refused to address, even with her family.

"If these were things that she actually did, she was not defining them as espionage," Emily Socolov told the Times. "If you feel that what you're doing answers to a higher ideal, it's not treason."

The Justice Department did not return a message for comment Tuesday. New York lawyer Irwin Warren, who filed the lawsuit on behalf of Socolov, did not respond to a request for additional information.

The lawsuit says Socolov wants the records for a book "that places her late mother's tribulations in the greater context of the Cold War." Socolov, who describes herself as a folklorist, is a visiting scholar at UT's Schusterman Center for Jewish Studies.

She made her first open records request in 2012, the year after her mom's death, and then made another the following year. The FBI released 10,751 pages, but the lawsuit states 1,300 are incomprehensible because of redactions. Another six pages were withheld in their entirety, the lawsuit says.

Their basis for withholding the records include concerns over national security and a duty to protect the identities of confidential sources. But, the lawsuit says, the sources are all dead or unlikely to be alive, and the surveillance tactics used in the 1940s are now obsolete.

"But to the extent they do, those techniques are far from secret: they are well-known to anyone who has watched a Cold War spy movie (or an episode of 'The Americans')," the lawsuit states.